Clark's (Kent and Luthor) secret is made up of a combination of five (at times varying) truths:
- He was born as the Kryptonian Kal-El, an alien from the planet Krypton.
- As a Kryptonian under a yellow sun, he has extraordinary powers.
- He has weaknesses: kryptonite (especially green kryptonite) and magic.
- Clark Kent uses his powers to save people and fight crime: first anonymously in Smallville, then later under the guises of the Good Samaritan, Red-Blue Blur, The Blur, as well as finally Superman in Metropolis (Earth-1). Clark Luthor uses his powers for personal gain and domination, willing to commit murder to do so: using the guise of Ultraman he rules Metropolis as a tyrant with an iron fist (Earth-2).
- Clark believes that he is responsible for the 1989 meteor shower, when his spaceship arrived in Smallville. The meteors caused many deaths (including Lana Lang's parents): it also caused many mutations, resulting in a number of psychotic villains. In this way, Clark always believed himself to be indirectly responsible for many of the bad things that have happened in Smallville. However, it was revealed in Season Seven's Apocalypse, when he traveled to a reality where his ship never made it to Earth, that the meteor shower would have happened anyway and, without him in the picture, the planet would have been worse off. This lifted a huge weight off of Clark's shoulders and he soon began to step out of the shadows and fight crime as the vigilante known as The Blur, as well as subsequently Superman.
In addition to his own secret, Clark tries to conceal related information as much as possible (his spaceship, other Kryptonians, Brainiac, the Phantom Zone, phantoms, the meaning of the cave writing, his fortress, the crystals, others with special abilities (including his dog), time travel, parallel worlds, etc.). He also tries to conceal his feelings for Lana and Lois whenever he feels that their safety and/or happiness are at stake. (For example, as long as he thinks that Lana loves Whitney, he doesn't interfere.)
Learning Clark's Secret
It often takes time for someone in Clark's life to learn his full secret, if they ever do.
Clark discovering his powers
- Clark displayed super strength as a kid, although his parents taught him that he shouldn't tell anyone else about them.
- He discovered his super speed at the age of 6. (Transference)
- At the age of 14, Clark discovered his invulnerability when he was hit by Lex Luthor's car. (Pilot)
- When Clark asked his father about his strange powers, Jonathan told him that Clark had landed in a spaceship on the day of the meteor shower. (Pilot)
- Clark encountered kryptoniteand felt sick while playing near Creekside Foundry with Pete Ross and Greg Arkin as a kid. (Metamorphosis).
He was also weakened by Lana's necklace, (Pilot)
but he didn't know why until Coach Walt Arnold trapped him in a sauna with meteor rocks and he figured out that those made him weak. (Hothead)
- Clark discovered his X-ray vision after a football training in the boy's locker room. (Hothead)
- Clark discovered his heat vision while watching a sex-education video in the biology class. (Heat)
- Clark used his super leap ability for the first time to jump from the Daily Planet skyscraper to the LuthorCorp Plaza skyscraper where Martha and Lionel were held hostages. (Insurgence)
- Clark learned from Dr. Swann that he had come from the planet Krypton. (Rosetta)
- Clark discovered his super hearing when he was blinded by a reflection of his heat vision at green kryptonite. (Whisper)
- When re-programmed as Kal-El, Clark showed the ability of flight (Crusade).
Back to his normal self, he was not able to use this ability again until Finale, Part 2 (the jump onto a nuclear missile in Hidden was rather a super-leap than a flight).
- When Clark had caught a cold, his sneeze blew the barn door off its hinges. This led Chloe to suggest he might have a super breath which proved to be true when he blew down a steel door. (Sneeze)
- The voice of Jor-El told Clark further details of his origin and his destiny. (many episodes)
Clark disclosing his powers to other people
- Clark showed his powers to Pete Ross after Pete had found the spaceship, as well as he told him about his alien origins (Duplicity). At that point in Season Two, Clark himself didn't know where he came from, telling Pete that "I don't know where that ship brought me from." Pete discovered Clark's weakness later in that same episode, when Clark told him that he's "allergic to the meteor rocks." Pete's difficulties in keeping Clark's secret, leading to his decision to leave Smallville (Forsaken) prevented Clark from disclosing his secret to further people, even from telling it to Lana.
- Under the influence of red kryptonite, Clark showed off his invulnerability in front of Ted Palmer and Lionel Luthor by firing a gun into his palm and then dropping the bullets. Even if Lionel was blind at this time and Ted Palmer was later killed, it is shown that Lionel has collected the deformed bullets. (Red)
- Clark uses his Heat vision in the presence of Cyrus Krupp, who belived himself to be an alien, in order to save him from attackers. (Visitor)
- Clark used his powers in front of Alicia Baker to prevent an elevator accident. (Obsession) She overheard him talking with his parents about his vulnerability to kryptonite, as well as later used both green and red kryptonite against him. It is unlikely that she ever learned about his alien origins, as she repeatedly told Clark how similar they were, since they both had secret powers that other people didn't understand.
- Clark told Chloe the rest of his secret, especially his alien origins, when she told him that she knew already about his super strength and speed. (Arrival)
- Clark showed Lana Lang his powers and proposed to her in the Fortress of Solitude. But then, Lana was killed in a car accident and Clark used a crystal to go back in time to change it. In doing so, Clark decided not to tell Lana his secret so that Lana neither learned the secret nor was proposed to. (Reckoning)
After Lana had secretly witnessed Clark's powers at the day of her marriage (Promise), Clark told her he was an alien shortly before she faked her death. (Phantom)
- Clark used his heat vision to help Oliver Queen in his Green Arrow suit to escape from Lois who was about to unmask him to learn his identity. He then stopped Oliver who rode away on his motorcycle and said he owned him one from which Oliver learned about Clark's super powers. (Arrow)
- Clark showed Javier Ramirez his super speed to save him from the police. (Subterranean)
- Clark showed Richtor Maddox his invulnerability to be admitted to his underground fight club. Maddox was shortly after killed by Titan. (Combat)
- Clark disclosed Lois Lane his secret twice in an alternate timeline:
He used his powers in to prevent Lois from being arrested when he was taken by Jor-El to an alternate universe in which he never had arrived at earth. Lois's immediate reaction was to assume that he was a meteor freak and she said "Pretty handy having a meteor freak on my side." Clark corrected her misunderstanding, saying, "I'm not a meteor freak." (Apocalypse)
Clark told Lois his powers and his alien origin so she could write an article about him instead of Linda Lake. When Clark reversed time, this never occurred. (Infamous)
Clark finally told Lois that he was the Blur in the main timeline after she had already reckognized him by a kiss. Clark said the only way they can share a life together is if she knows his secret and that there's no one else he'd rather take that chance with. Lois, overjoyed, pounces on Clark in a romantic embrace and asked asks what took him so long to reveal it to her, whereupon Clark is shocked by her already knowing the truth. (Isis)
Clark told Lois about his s alien origins in the following episode. (Harvest)
- Clark told Jimmy he was the Red-Blue Blur after Jimmy had witnessed his wound healing instantaneously. (Doomsday) He referred to the episode Identity when Jimmy connected the Blur with Clark based on photos and Clark threw off this suspicion by getting Oliver Queen to dress up in a red-and-blue costume and save Jimmy from a mugging.
- Clark used his powers in front of Alec Abrams, who temporarily was converted into Warrior Angel, when he saved Chloe from falling off a skyscraper's rooftop. Alec, converted back to his boy shape, gave him an image he had painted of the red-blue Blur with "RBB" on his chest, but stated he would like the "S" better.
Other people discovering Clark's powers
Other people in Clark's life also tended to learn his secret over time, some of them have yet to even learn his full secret:
- Sam Phelan accidentally saw Clark stopping a bus that went out of control. He kept the secret and used it to blackmail Clark until he was shot during a robbery. (Rogue)
- Kyle Tippet saw Lex, who was under the control of Bob Rickman's handshake, shooting Clark with an automatic weapon, while Clark dodged the bullets. He promised to keep Clark's secret. (Hug)
- Ryan James learned Clark's secret due to his telepathic abilities because he read the minds of Martha and Jonathan. He even went to see the spaceship in the cellar where Clark found him. (Stray)
He promised to keep the secret and did so until he died from a brain tumor. (Ryan)
- Roger Nixon spied upon Clark, discovered his secret and even found the spaceship. (Tempest)
He was shot before he could publish his discoveries. (Vortex)
- Bart Allen, who had the ability of super speed, discovered that Clark could run almost as fast as he himself. (Run)
- Chloe Sullivan discovered Clark's super speed and strength when Alicia tricked Clark into stopping a moving car while Chloe was watching. (Pariah)
She learned about Clark's vulnerability to kryptonite when Jonathan used kryptonite to subdue a possessed Clark (Jonathan thought that Chloe was unconscious at the time). (Spirit)
An amnesic Clark showed her his other powers although he didn't remember it later. (Blank)
Clark then told her about his alien origins when she was in a Yukon hospital. (Arrival)
She presumably deduced that Clark came down during the first meteor shower shortly after, although Clark mentioned his spaceship to her. (Mortal)
When Brainiac went back in time to kill baby Kal-El, Chloe knew right away that Brainiac was trying to prevent Kal-El from getting into his spaceship. (Apocalypse)
- Kevin Grady, Lois Lane and Sheriff Nancy Adams learned Clark's secret after watching him save Chloe by catching two falling columns. However, all the three women had their memory wiped by Kevin. Since he only took them away a few minutes of memory, Chloe still remembered what she learned of Clark's secret months ago and earlier that day. (Blank)
- Arthur Curry saw Clark absorbing the explosive force of a bomb with his body. (Aqua)
He later became a member of the Justice League.
- Linda Lake, in the form of water in a bathtub, overheared a conversation between Chloe and Clark from which she learned that Clark was an alien. She prepared an article, but her computer was destroyed by Chloe and she was run over by a car before she could publish it. (Hydro)
Two years later, she re-appeared and published her article. However, Clark went back to the past using the Legion ring and succeeded in preventing the publication. (Infamous)
- Before Clark told Lana Lang he was an alien, she had thought he was infected by kryptonite.
She assumed Tobias Rice identified Clark as a meteor freak, but he actually identified Chloe Sullivan and claimed Clark as a normal person. (Freak)
She tricked Clark into displaying his powers just before she got married to Lex Luthor (Promise).
She had already found out about Kryptonians' weakness to kryptonite from Lionel Luthor (Arrival).
- Ben Meyers secretly witnessed Clark catching a bullet intended for Rachel Davenport. He kept the secret even after he was taken to Belle Reve. (Action)
- Jimmy Olsen found out Clark's secret when he saw Clark's cut heal instantaneously before his eyes. (Doomsday)
- Sebastian Kane who could read minds by touch learned Clark's secret when he touched Clark just before Clark knocked him out. (Identity)
- After Clark had disclosed his secret to Lois Lane twice in an alternate timeline, she finally learned the secret in the real world after Clark kissed her as the Blur and she recognized the man she loved. (Salvation)
People have discovered Clark's superpowers several times, but Clark rarely trusts people with the full secret of his alien origins, his indirect role in causing the meteor showers, as well as his vulnerability to kryptonite.
The only people who know Clark's full secret are:
- Friends and Family on Earth
- Clark's adoptive parents, Martha and Jonathan Kent, knew Clark's secret since they found him, as well as found out about his powers and weaknesses as he did.
- His childhood best friend Pete Ross was the first friend to learn Clark's secret in Season 2's Duplicity: Pete discovered Clark's ship after it was lost in the tornado and Clark was forced to reveal the truth to stop Pete from telling anyone else.
- His best friend during his college years, Chloe Sullivan, learned Clark's full secret by Season Five's Arrival, but had already discovered his powers in Season Four's Pariah when she witnessed Clark catching a car after Alicia took Chloe to a position where she could see him in action.In Season Four's Blank she further learned of his X-Ray Vision and Heat Vision. In Season Eight's Abyss, Chloe's memory of Clark's secret was wiped and Jor-El, at Clark's request, did not restore it. In Season Eight's Legion, Chloe regained her memory of Clark's secret after the Legion of Super-Heroes removed Brainiac from her body.
- Clark's girlfriend Lana Lang didn't learn Clark's full secret until the end of Season Six, in Phantom, but she had already secretly witnessed his invulnerability in Crimson and his strength, speed and heat vision in Promise.
- His friends and fellow superheroes in the Justice League are all aware of Clark's alien origins. (Odyssey, Hex, Idol)
- Jimmy Olsen finds out Clark's secret in Doomsday after witnessing Clark use his abilities, but suspected his identity as the Red-Blue Blur in Identity.
- Chloe's assistant at the Watchtower, Emil Hamilton, seems to display knowledge of Clark's secret throughout Season Eight and Season Nine.
- Alec Abrams, a 12 year old boy, discovered that Clark was the Blur after Clark revealed himself to calm him down and talk about heroes. He knows Clark has powers, but not the full extent of his secret.
- Lois Lane learned Clark's secret in Season Eight's Infamous but after Clark altered time, this event never happened. Then after traveling to an alternate future, she learned it again, although she only remembered basic visions of the future. She subconsciously remembered in Season Nine's Idol and tried to prove to herself Clark was the Blur, but she later believed she was wrong. After a passionate kiss, she finally realized he is the Blur in Season Nine's Salvation. Clark later admits to Lois on his own that he's the Blur in Season Ten's Isis, where Lois joyfully reveals she already knows.
- The members of Justice Society of America knew Clark's secret since the events in Absolute Justice.
- Bruce Wayne discovers Clark's alien heritage through the means of a collaboration of information he had gathered together. Clark also reveals his secret identity to him as well.
- Clark's birth parents Jor-El and Lara-El knew that the yellow sun will give Clark powers.
- Other Kryptonians, including Kara, Raya and Dax-Ur. Clark revealed his identity to them shortly after meeting each of them.
- Evil Kryptonians such as Zor-El, General Zod, Faora and the Disciples of Zod.
- Davis Bloome found out Clark's secret in Eternal.
- Conner Kent, a half-human/half-Kryptonian clone of both Lex and Clark, found out that Clark was The Blur when Clark demonstrated his abilities to stop him from leaving the farm in Scion.
- The Kryptonian computer Brainiac knew Clark's identity as Kal-El immediately.
- Martian Manhunter, who was friends with Jor-El on Krypton.
- Bizarro, who received all of Clark's memories after cloning a whole body from Clark's DNA.
- The Kryptonian monster Doomsday knew Clark's secret as he was programmed with sensing Kal-El. (Bride)
- The Legion of Super Heroes knew Clark's secret since Legion, having learned of his legend from history books.
- Additionally, Booster Gold, also from the future, also knows Clark's secret from historical records. (Booster)
- The alien force Darkseid learned about Clark's secret and attempted to make Clark his puppet and use him as a weapon against mankind. (Supergirl)
- Veritas Members and Associates
- Lex Luthor discovered Clark's secret after activating the Orb and journeying to the Fortress where he confronted Clark. Lex learned that Clark was the Traveler from Brainiac (disguised as Kara) at the end of Season Seven, in Arctic. Lex had discovered parts of his secret several times before this event, but each time concluded in a circumstance that caused him to either forget or in one instance, the timeline was reversed as if it had not happened at all. When he was brought back to life by Darkseid, Lex confronted Clark, still bearing the knowledge of his secret, but after he confronted Tess and killed her, she infected him with a neurotoxin that took away his memories of everything that happened over the preceding years, including Clark's secret.
- Lionel Luthor discovered Clark's secret when he became the oracle of Jor-El during Season Five. (Cyborg, Mercy).
- Dr. Virgil Swann contacted Clark when he saw Kryptonian symbols burned onto Clark's barn, as well as taught Clark about Krypton. (Rosetta)
- Dr. Bridgette Crosby was a colleague of Dr. Swann, as well as knew about black kryptonite. (Crusade)
- Patricia Swann inherited her father's journal, as well as met Clark after Lionel introduced them. (Traveler)
- Edward Teague learned that Clark was the Traveler when Clark showed up at St. Christopher's Cathedral in Montreal, as well as used kryptonite against him. (Quest)
- After months of suspicions, Tess Mercer finally found out about Clark's origins after getting information from her assistant Eva Greer while she posed as Chloe before her death, as well as destroyed the black crystal so Clark could fulfill his destiny. (Injustice)
- Dr. Helen Bryce seems to be suspicious that Clark Kent is not human when she analyzed his blood when he became fatally ill.
- Alternate Reality beings
- Clark Luthor as an alternate version of Kal-El (which Clark Kent is in relation to Luthor) knows of his counterpart's origins, abilities and weaknesses and vice versa.
- Tess Luthor as Clark Luthor's adopted sister had at least some level of knowledge of his origins, powers and weaknesses. She was also aware that he was Ultraman (feared as a vicious murderous tyrant). However she blamed Lionel for Clark's villainous ways.
- Earth-2 Lex Luthor as Clark Luthor's adopted brother was aware of his origins, powers and weaknesses. He was also aware of how he used his abilities and acted to oppose him and was eventually killed by his adopted brother with their own father's approval.
- Earth-2 Lionel Luthor as Clark Luthor's adopted father had full knowledge of his origins, powers and weaknesses. It was Lionel who set Clark on the path to becoming Ultraman. When Earth-2 Lionel came to Earth-1, he had full knowledge of his adopted son's alternate counterpart's origins, powers and weaknesses.
- Earth-2 Oliver Queen: While not clear whether he knew Clark was an alien, he had some knowledge of his powers and weaknesses (courtesy of Earth-2 Chloe Sullivan in part). He eventually learned that Clark was the murderous tyrant Ultraman.
- Lois Queen: While not clear whether she knew Clark was an alien, she had some knowledge of his powers and weaknesses (Courtesy of Chloe and Oliver of Earth-2). She eventually learned that Clark was the murderous tyrant Ultraman.
- Earth-2 Chloe Sullivan: Witnessed Clark Luthor's murder spree at Smallville High on her graduation day. Nearly became a victim herself but was saved by her kryptonite necklace which made Clark retreat. Eventually became aware of Luthor being the murderous tyrant Ultraman. Not clear whether she knew Clark was an alien being.
- Earth-2 Jonathan Kent: Whether he ever met Clark Luthor is unclear. However, he did become aware of his identity as Ultraman as well as weakness to Green Kryptonite, after Earth-2 Oliver Queen exposed these facts to the city of Metropolis on Earth-2. He eventually met Ultraman's counterpart who was his adopted son from an alternate reality and the two eventually formed a bond with one another.
Several episodes have focused almost entirely on Clark's secret, as well as whether or not he reveals it to the people in his life:
- Season One, Hug - Lex, under the influence of Rickman, sees Clark use his abilities but loses his memory of the event due to the effects of Rickman's handshake wearing off.
- Season Two, Duplicity - Pete finds a spaceship and is going to use it to get famous, whbitions, Clark's desires to reveal his secret to his friends and the world are magnified. The ring is eventually destroyed, thus prompting Clark to maintain his secrecy.
- Season Two, Rush - Under the influence of the Kawatche Caves's Parasites, Pete expose Clark to red kryptonite. During this time, Clark reveals his powers to Chloe, but her memory of the parasite induced activities are gone once it's out of her body.
- Smallville #6, ID - Clark considers telling Lana his secret, as well as plans to do so when they are alone at the Talon. After destroying a bullet that bounced off him and nearly hits Lana, he decides against it.
- Season Three, Shattered - Clark destroys a car moving towards him in front of Lex. While Lex mentions this he appears to be delusional due to some drugging by Lionel's servants.
- Smallville #8, Captive - With the knowledge of Clark's secret, Lex begins to plan on how to take advantage of it. After a while, he starts to understand why Clark had kept his powers a secret and vows to respect it.
- Season Three, Asylum - Lex has refrained from mentioning Clark's secret to anyone. Clark intends to free him from Belle Reve before he is able to have his memories of the past six months removed (even if it means that Lex will know his secret). Clark is unsuccessful in prevent the electrotherapy from occurring, thus Lex's knowledge of his secret is gone.
- Season Three, Truth - Chloe gets truth coercion powers, as well as tries to use them to find out Clark's secret. Her power doesn't work on him, as well as she gets in a car crash before she can ask Clark's parents.
- Season Three, Forsaken - Clark decides to tell Lana his secret. Just then, Pete gets tortured for Clark's secret, as well as decides that keeping Clark's secret is too hard. Clark changes his mind, as well as decides not to tell Lana his secret.
- Season Four, Blank - Kevin, a boy who can cause people to temporarily lose their memory, turns his powers on Clark and causes him to have total amnesia - to the point where Clark forgets he has superpowers. Chloe has figured out that Clark has powers, and so she looks after him and teaches him about his superpowers while simultaneously trying to keep them secret. Later, Clark recovers his memories but forgets about his day.
- Season Five, Reckoning - Clark reveals his secret to Lana and proposes to her. She accepts, but dies shortly after. He resets time, as well as decides not to tell her his secret.
- Season Six, Crimson - While both of them are under the influence of red kryptonite, Clark reveals his powers to Lois due to being compared to Oliver. After Lois is no longer under the influence of the Kryptonite, she forgets everything that happened, including Clark's secret. Lana, however, is beginning to discover Clark's secret as she observes a chisel that Lex tried to stab him with (noticing that it's crooked).
- Season Six, Phantom - Lana declares her intention to leave Lex to Clark only to also reveal that she will be leaving Smallville. Clark reveals his secret to her, only to discover that she knew it for quite some time.
- Season Eight, Identity - Jimmy deduces that the "Good Samaritan" saving citizens of Metropolis is Clark. He confronts Chloe and Clark, who both deny it. Clark is adamant that Jimmy not confirm his secret, since he firmly believes that anyone that knows his secret is in danger. Clark enlists Oliver Queen's help in staging a rescue of Jimmy by the Good Samaritan, so that Clark has an alibi. Also, Sebastian Kane uses his memory-reading powers to learn Clark's secret: Chloe then kills Sebastian by overloading him with information, presumably downloaded from Brainiac.
- Season Eight, Abyss - Chloe's memories are being deleted by Brainiac, including her knowledge of Clark's secret. Clark brings her to the Fortress of Solitude to have Jor-El restore her memories: her memories are restored but at Clark's request, she has no recollection of Clark's powers or of Krypton. Prior to Chloe's memory loss, Clark brought up the people in his life who left or died knowing his secret including Jonathan, Pete, Lionel and Lex.
- Season Eight, Bride - Clark informs Oliver and Lana of his choice to prevent Chloe from remembering his secret. Lana states that she understood his need to keep her in the dark, but tells him that if he erased her memories that she could never forgive him.
- Season Eight, Legion - By the 31st Century, the citizen of Earth, including The Legion of Super-Heroes are aware that Clark is an alien and that he will one day become Superman. Chloe's memories of his secret return after Brainiac is extracted out of her.
- Season Eight, Infamous - Clark tells the whole world about his secret, but Linda Lake makes the world think he is an alien who has come to destroy the earth. Clark uses the Legion ring to go back to before Lake wrote her story, as well as defeat her.
- Season Nine, Idol - Lois finds out that Clark is in fact the Blur. Lois states that his secret is too important to be revealed even at the cost of her own life. Later on Lois gets a phone call from the Blur (Chloe) saying that he is sorry that he forgot to call her. Clark's secret is safe thanks to Chloe.
- Season Nine, Salvation - Lois discovers that Clark is the Blur through a passionate kiss.
- Season Ten, Lazarus - Lois witness Clark's resurrection and decides to keep it a secret until Clark is willing to revealed his secret to her himself.
- Season Ten, Homecoming - When Clark is accidentally transported to the future in the year 2017, He discovers that Lois Lane is fully aware of his Kryptonian heritage and abilities and that she goes to great lengths to protect Clark's Secret Identity as Superman.
- Season Ten, Isis - Clark revealed his secret to Lois willingly to which she responds what took him so long. Clark is both surprised and overjoyed that Lois knew and protected his secret as they kissed passionately in the file room of the Daily Planet .
- Season Ten, Harvest - Lois learns about Clark's Kryptonian heritage, the effects of blue kryptonite towards him and many other things about Krypton and its race when he gives her Swann's journal.
- Season Eleven, Guardian - Clark asks Lois if her father could possibly know that he's The Blur/Superman as he recalls a conversation they shared.
- Season Eleven, Detective - Clark reveals his secret identity to Batman, when his life is in critical jeopardy due to kryptonite laced bullets fired upon him by The Prankster. Clark tells Batman to contact Lois who tells him how to save Superman from dying.
- Season Eleven, Olympus - Clark reveals his secret identity to Diana in order to gain her trust and help her track down the creatures that attacked her and Lois prior.
- Clark's guilt over indirectly causing the 1989 meteor showers was behind his greatest fear: he feared that Lana would reject him once she realized "his" meteors had killed her parents. (Season Four's Scare) This part of Clark's secret has not been fully explored in Clark and Lana's relationship: by the time she discovered the rest of his secret at the end of Season 6, Lana had presumably already dealt with the death of her parents and was ready to move on.
- Jor-El showed Clark what would have happened if his ship had not made it to Earth: the 1989 meteor shower still would've happened, but Lex Luthor would become President of the United States and cause a nuclear apocalypse on Earth. This may have helped Clark overcome his guilt over his role in the first meteor shower.
- Clark's secret is sometimes perceived of as a burden by those who bear it. Pete told Clark that, "I walk around every day afraid that I'm gonna slip up." Pete moved away to Wichita, as he couldn't live with the risk that he might slip up and reveal Clark's secret. After Jonathan passed away, Martha was glad to learn that Chloe shared Clark's secret. (Vengeance)
- Both Chloe and Lionel found a sense of purpose after finding out Clark's secret, as well as were willing to do anything to protect him, including sacrificing their lives. Chloe refused to give up Clark's secret even while she was tortured and almost killed by Agent Vanessa Webber in Sleeper, Lionel refused to reveal the identity of the Traveler to Lex, who killed him in anger in Descent.
- Clark is not willing to sacrifice people's lives to protect his secret. He tried to save Dr. Steven Hamilton even though Dr. Hamilton had learned his secret. Clark was even unwilling to sacrifice someone's memories: Clark tried to prevent Lex from undergoing electroshock therapy to give him amnesia, even though Lex had witnessed him using his powers.
- Federal government agents have twice tortured Clark's friends, seeking to discover his secret. Chloe was tortured by Agent Vanessa Webber of the Department of Domestic Security, while Pete was tortured by FBI Agent Frank Loder.
- In Infamous, federal agents interrogated and shot at Clark in his house: they later started a manhunt for not only Clark but also Chloe, his best friend.
- Clark has revealed his secret and then "taken it back" three times. The first two times were with Jor-El's help twice. In Season Five's Reckoning, he told Lana his secret: after she died, he used Jor-El's time crystal to reset time. In Season Eight's Abyss, Chloe's memories are removed by Brainiac: Clark asks Jor-El not to restore her memories of Clark's powers or of Krypton. The last time, he revealed his powers to the world, but then later went back in time using the Legion ring.
- After Clark's secret was revealed to the world, Martha was forced to temporarily step down as Senator for the state of Kansas. (Infamous)
- It's interesting to note that by the end of Season Eight, every character in the opening credits, except for Lois, learns Clark's secret. Lois learns the secret in the Season finale of Season Nine and retains that knowledge to herself in Season Ten (acknowledging that she was "the last one to know".) until Clark tells her his secret willingly and Lois reveals that she knows. As of Season 10, every main character in the cast knows about his secret from the premiere onward which is the first time in the show's history this has happened.
- The meteor freaks and human antagonists that have found out Clark's secret while trying to kill him are rumored to have told the others in Belle Reeve.
- Clark has revealed his secret to Lois purposefully on three occasions. He, under the influence of red kryptonite revealed it to her in Crimson. Since both were infected, she forgot when cured. In order to prevent Linda Lake from manipulating him, he revealed it to her again in Infamous so she could tell the world but had to reverse the timeline so he didn't reveal it to her. He reveals it to her in Isis on his own, knowing she needed his honesty if they were going to share a life together.
- Clark has revealed his secret to three people as they were leaving his presence. He told Pete in Duplicity, who was driving off angrily because Clark had been lying to him. He told Lana in Phantom as she was leaving the barn, preparing to leave Smallville to get away from Lex. He revealed his secret to Lois as she was leaving the basement of the Daily Planet in disappointment because Clark had just said the Blur probably wouldn't reveal his secret to Lois as long as it put her life in danger.
- ↑ As revealed in Apocalypse, the meteor shower would still have happened even if Clark's ship hadn't made it to Earth.
- Secret Keepers - A list of people who have learned about Clark's powers (but don't necessarily know his full secret)..