Dramacon: When Christine presents Lida Zeff a copy of her first published work to autograph, Leda's reaction is something akin to a brief Heroic BSoD, followed by her putting on the puppy dog eyes to persuade Christine to Kill It with Fire.
In an episode of Lucky Star, Hiyori invites friends over to her house, only to be horrified when she finds them skimming through old sketches in her artbook.
In Panty & Stocking with Garterbelt, episode "Sex and the Daten City": Panty and Stocking are set to debut a movie starring them, and Panty accidentally reveals that she acted in a porno without realizing it at the time. The episode revolves around Panty thereupon setting out to destroy all the copies of the porno in existence. Panty then decides to edit Stocking out of the movie, and Stocking responds by uploading a secret copy of the porno to YouTube, where everyone can see it.
Getting away from this seems to be one of the motivations of the Yuuta, because he really couldn't stand the All the Other Reindeer treatment he had due his very extreme adolescent delusions.
Like Yuuta, Shinka resents her past life as "Mori Summer". Unlike him, however, she's not as good as him when it comes to facing the fact that her past delusions will always haunt her.
The case of Eita of Oreshura is somewhat similar to Yuuta, above, in which he was also trying to hide a bout of Chuunibyou. This is an important plot point—a notebook containing his fantasies was used by Masuzu to Blackmail him into her fake boyfriend.
In Bakuman。, after hearing that Eiji came up with the idea for his incredibly popular series "Crow" while younger, Mashiro decides to look at his drawings for inspiration. With most of them, he is surprised at how much he sucks, but he does actually manage to find one that serves as the basis for his and Takagi's first serialized manga, "Detective Trap".
Shido is horribly embarrassed by many things from his middle school days, including bad poetry, playing guitar, and general chuunibyou tendencies. Kotori is merciless in using these against him by threatening to make recordings public if he doesn't meet her standards.
Five years before the main plot, Kurumi used to wear an eye patch that covered her clock pattern eye. When Shido asks about it, the current day Kurumi's refusal to explain seems to indicate it's an embarrassing topic.
Shirobako uses this trope with the director character, Seiichi Kinoshita, whom had found early success in the anime industry but then directed the laughably badJiggly Heaven before restoring his reputation with Exodus! and Third Arial Girls Squad.
In the 3rd issue of The Joker spinoff comic the Joker kidnaps a cartoonist named Sandy Saturn who created the Peanuts parody Cashews, who as it turns out hates the strip and only draws the strip because of his contract. He gladly complies with his captor's order to draw pictures of the Joker beating and killing Charlie Cashew.
Nick Spencer's Spider-Man makes mention of Peter not being particularly fond of a period in his college career when he read some Ayn Rand and thought himself the new John Gait. (This doubles as a Mythology Gag to a contentious scene in the Lee-Ditko Spider-Man where he brushed off a group of (entirely non-political and jokey) protestors who wanted him to participate, which many readers have surmised was the heavily objectivist Ditko going full Writer on Board.)
Simon is not exactly proud of his involvement in a children's TV show as a character called Mr. Muscles, who dressed as a jungle man with Simon's sunglasses and, in-character, was a Dumb Muscle brute who took a pie to the face. Beast found the show channel-surfing and got a laugh out of the whole thing.
During Dark Reign, he came to regard his time with the Avengers as this and even tried to convince Steve Rogers not to reform the Avengers after Siege.
The My Little Pony: Friendship Is Magic fanfic Fluffershy (no link because it is NSFW, even if it is not a Lemon) is about her friends trying to find out if Fluttershy has an old shame. Pinkie Pie accidentally found a pornographic video which seems to have Fluttershy's rump on front, and a mixture of lecherous curiosity and genuine concern causes her friends to investigate. She both has and hasn't. She was just an extra in the film and didn't do anything remotely sexual, but still considers it an old shame. The filmmakers put her flank on the cover even if you don't get to see her have sex in it because Covers Always Lie.
This trope is part of the plot of Notting Hill, where the female lead is a movie star whose pornographic past turns up in the press halfway through the movie.
In Music and Lyrics, Alex Fletcher openly concurs with the general critical consensus that his only solo album was, in the words of what was apparently the kindest review, "a crass, contrived effort not fit for a dentist's chair." When Sophie reveals she's bought and listened to a copy, he immediately produces his wallet to refund her.
In Airheads, Chazz is forced by the SWAT leader to reveal to that he was a high school dork. Instead of losing the metal crowd that had gathered, however, his confession spurs people in the crowd to their embarrassing secrets of geekery. By the end, the crowd is even more supportive of the Lone Rangers' hostage-taking.
In Billy Madison, Principal Anderson used to be a professional wrestler known as "the Revolting Blob" until he accidentally killed an opponent during a match. Eric Gordon uses this to blackmail him into claiming that Billy bribed him into passing his classes.
In Lois Lowry's Anastasia Krupnik series of children's books, the eponymous character's father is a literature professor who has published three poetry collections. In an invocation of the trope that authors always think their early work is terrible, he is so embarrassed by the quality of the first collection that he tries to discourage Anastasia from reading it.
In Gregor and the Code of Claw, it's revealed that Bartholomew of Sandwich resorted to poisoning the moles to get their land. It was thought they were all killed by this tactic, and it poisoned everyone else's opinion of the humans.
In Harry Potter, it's revealed that Albus Dumbledore was once buddies with a dark wizard named Gellert Grindlewald, who was the wizarding equivalent of Adolf Hitler, and they planned to use magical artifacts called Deathly Hallows to establish a new world order and enslave Muggles. Dumbledore's regret over his younger foolishness, coupled with the ensuing death of his sister Ariana, helped him become the most powerful good wizard and protector of Muggles that Our Boy Harry knew.
In the X-Wing Series, Garik "Face" Loran starred in some pro-Imperial holodramas during his youth, which he naturally regrets doing after joining the Rebellion.
Robin was a Canadian pop star "Robin Sparkles" and her hit songs "Let's Go To The Mall" and "Sandcastles In The Sand", as well as staring in a Canadian edutainment show. She is so humiliated by this that she would rather admit to being secretly married or doing porn before admit being Robin Sparkles.
Ted feels this way about his "rereturn" where after he had confessed his love to Robin, he "rereturned" to her apartment to try and kiss her but was so drunk that he threw up on her carpet and ran away.
The above incident was covered in the episode "Game Show" where it revolves around each of the character's Old Shame:
Marshall was seen on the toilet by Lily's kindergarten class.
Lily recalled how Marshall's mother overheard the couple having sex via phone call.
Barney's video to his girlfriend Shannon, begging her to come back to him (and serenading her) while as a hippie counts.
Future!Ted is often embarrassed by Present!Ted's antics in some stories. Similarly, Present!Ted is often embarrassed about College!Ted.
House discovers Wilson starred in a student film that was later turned into a porno by adding sex scenes from another actor. This is quickly spread to the entire hospital, and House replaces Wilson's usual movie posters with posters from the porno.
In one of House's more convoluted plans to attract Cuddy, he allows Lucus to find a picture of him as a college cheerleader. Lucus originally believes that the picture was planted by House to manufacture false embarrassment—which was probably House's plan, but Lucus is able to determine that the picture was real. When confronted, House explains that he did it for a girl, which Lucus believes makes it more shameful.
In Community, when Jeff and Annie are running for student government president, Annie brings out Jeff's audition tape for The Real World: Seattle. It begins with him singing a parody of George Michael's "Faith", "Gotta have that Jeff, Jeff, Jeff".
Richard Castle joins the murder investigation in the pilot episode partly because his curiosity is stoked over why the killer decided to base his murders on Castle's self-described 'lesser works' rather than his later, better ones. It also helps him peg Detective Beckett as a Fangirl of his works when she accidentally reveals that she's familiar with those lesser works.
Despite not being involved in the creative industries, Detective Beckett also has an example, curiously enough — it involves photos of a shoot during her short-lived career as a model when a teenager.
In "The Final Frontier", this trope actually leads to the murder: The actress who played Lt. Chloe on the short-lived Nebula 9 hated the show so much that when she found out that the woman who owned the rights to it was selling them to a major film company so it could possibly remake the series, she killed her before she could finalize the deal.
In Angel a dream sequence reveals that Angel attended Barry Manilow concerts. Which turned out to be a kind of accidental psychic torture for his alter-ego Angelus.
In Party Down Henry is constantly reminded of his role in a series of beer commercials by party guests recognizing him from them. Again, he is embarrassed when Casey recognizes him from an old indie movie in Steve Guttenberg's collection.
Bones: Medical Examiner Camille "Cam" Saroyan appeared in a low budget, very cheesy vampire movie called Mother Suckers to help pay for medical school. Upon learning this fact her co-workers of course track down a surviving copy to see just how bad it really is. Much to Cam's embarrassment.
On one Clip Show episode of Friends, which has a Frame Story of being Soap Opera Digest's interview with Joey, several of Joey's acting roles depicted in early episodes are implied to be this. Such roles include his lead role in a musical about Sigmund Freud and his role as an extra in a porno (taken after he couldn't bring himself to be the lead). The most bizarre one is in a play that we are only shown a small part of, which seems like a normal play until a lit-up ladder comes from the ceiling and Joey's character explains that he is going to "Blargon 6" and will return in 200 years.
The Big Bang Theory Penny's role in "Serial Ape-ist" and its sequel are destined to be this if she ever realizes her dream of becoming a famous actress. She reluctantly accepts the sequel job after a talk with recurring guest star Wil Wheaton that touches on this trope in relation to his post Star Trek movies. He is later revealed to have been cast in the same embarrassing movie as Penny.
Quinn participated in pageants when she was a little girl.
Zoey was the model for baby suntan lotion, with her naked butt on the bottle.
When PCA was still all-male, Chase was cast as the female lead in a school play.
Hikari Sentai Maskman has an episode where Takeru/Red Mask bragged that he was a model student, which was probably true, though through a Time Travel plot, the team came across young Takeru, who was instead a Bratty Half-Pint extraordinary. Apparently, after his future self encouraged him to be a man that faces every challenge, young Takeru started his Character Development to be a better man, but was so ashamed of his bratty self that he preferred to skip about that bratty phase when asked about his past, or just use the 'model student' lie.
From Married... with Children: Gary considers that one time when she invested her money into one of Larry Stork's schemes, which lost all the money she put into it, as this. She continues to harbor grudges even when she's quite well-off and claims she would exact revenge should she see Larry again. Sure enough, Larry shows up at her shoe store a bare minute later, and Gary proves she meant business by punching his lights out (though she winces from the recoil afterwards).
Agents of S.H.I.E.L.D. reveals in the first season that modern-day HYDRA agents are sick of being reminded of their organization's former association with the Nazi party. Sure, they're all for totalitarian dictatorship and the removal of free will, but racist genocide is a step too far.
On Star Trek: Enterprise, United Earth Minister Nathan Samuels was once part of an Absolute Xenophobe movement called Terra Prime, though he severed his ties with the group and admits his folly. When Captain Archer finds out about this, he doesn't expose Samuels but does use this bit of intel as leverage to take control of an investigation of Terra Prime activities.
Invoked by the Chely Wright song "Back of the Bottom Drawer", which is about a great deal of detritus gathered from former boyfriends, such as stolen hotel keys, napkins with poetry on them, et cetera.
Also, "'Fore She Was Mama" by Clay Walker. The narrator recalls finding a box full of photographs that show his mom as a rebellious, motorcycle-riding, marijuana-using wild lady, and is incredulous that she used to be such a person. He and his brother tease her about it, and she ends up burning the box.
Ivy once created a Sonic the HedgehogOC called Ziz the Eagle. She's now deeply embarrassed about it, and would be aghast if anyone found it out. That said, she still has enough sentiment towards it that she named her drone after it.
When she was younger, gang leader Nadine was once signed up for tap-dancing classes by her mother. Once.
In Jagged Alliance 2, one of the mercenaries from the previous installment, Reverend Clyde Potter, is missing from the current A.I.M. roster. His bio states that he has returned to his original ministry, returns his retirement checks and denies ever having been affiliated with A.I.M..
In Dumbing of Age, Dorothy and Joyce discover that Walky had appeared in an old episode of Hymmel the Humming Hymnal as a pink mouse. Walky had forgotten about it until he saw the video, and immediately considered it this, partly because of the aformentioned pink mouse and it being a Christian propaganda video, but also the fact that he's in it, and his twin sister isn't, makes Walky realize that Sal may have a point about the Parental Favoritism stemming from racism.
In the xkcd comic Old Files, Cueball has this reaction to looking through his high school work and discovering he wrote poetry. The Alt Text has him finding an Animorphs fanfic and quickly deleting it.
Strong Bad of Homestar Runner refers to his first attempt at drawing a dragon as the "S-is-For-Sucks" Dragon. However, in the Trogdor's 5th birthday toon, he sings a song about the S is For Sucks Dragon, then indicates that he's sick of Trogdor, claiming that "you Internet types" ruined him.
Yamcha of Dragon Ball Z Abridged recorded a hit song. According to him, he needed the money, and no, it wasn't worth it.
In Slacker Cats it turns out Mrs Boots had done some "mistakes" as a kitten like dressing up as a pirate and a fireman in "Cats Do the Cutest Things". Eddie and Buckley blackmail her with it.
In Total Drama World Tour, Sierra brings up Chris's earlier career (making bad movies about talking cats, being on a cooking show that lasted one episode, and being in a boy band). Chris is not amused, to say the least.
On Phineas and Ferb, Linda Flynn has mixed feelings (mostly embarrassment) about her short-lived career as a pop singer, Lindana, back in the eighties.
The South Park episode "It's a Jersey Thing" has Sheila hiding her past as a hardcore partying Jerseyite.
Pickles from Metalocalypse did not originally gain fame from his current band Dethklok, but from a much cheesier glam metal band called Snakes n' Barrels which he does not like being reminded of.
In the Rugrats episode "Baby Commercial," Betty regrets having Phil and Lil star in a commercial for diapers. When Didi sees it on television, Betty briefly mentions the horrors she experienced with Phil and Lil on the set before quickly offering a cup of coffee. When the director of the commercial stops by to recruit the twins for another gig, Betty immediately refuses and slams the door in his face.
In the episode "Bart of Darkness", Krusty the Clown is extremely embarrassed by his 60s "Classic Krusty" shows, which were more like a late-night talk show a la The Mike Douglas Show.
Not as embarrassed as by the time he imitated Jim Morrison. ("Oh, man, what was I on?")
Another episode, I'm Spelling as Fast as I Can, has the KBBL Booberella show Matine of Blood and Comercials showing Frankenstein and the Harlem Globetrotters Meet the Mummy and the Washington Generals starring a young Ray Romano. The broadcast stops as Booberella warns that Romano sued for a temporary injunction to stopping them from showing the movie, and that they will fight the injunction as they show something else.
"The Man From Pluto" is this to Wally in Mission Hill. It was meant to be his magnum opus, until he spotted Gus and couldn't keep his love life separate from his work. He actually changed his name to avoid any association with it. Towards the end he does come to accept it, though, when he realizes the movie is one huge valentine to his lover, and when he sees how many people love it.
After the events of the Thanagarian Invasion in Justice League, Shayera considers her original costume and even the name "Hawkgirl" to be this, changing into a new, more down-to-earth outfit and referring to herself only by her real name.
In the episode "Sonic Rainboom", Rarity enters the Best Young Flier Competition with a set of magical wings. She flies too close to the sun, causing her wings to disintegrate. After she knocks out the Wonderbolts during their attempt to rescue her, Rainbow Dash saves them mere inches before they hit the ground. When these events are brought up much later in "Sleepless in Ponyville", Rarity blushes, clearly regretting the scare she caused.
In "The Crystalling Part 1", we see that Starlight Glimmer is really not too happy over her actions as the main antagonist back in Season 5, becoming The Atoner yet not feeling worthy of being Twilight Sparkle's student in friendship. In the following episode, we find out that Starlight's old friend, Sunburst, the pony who accidentally started her on her evil path, is equally in the same boat - turns out that he's great with magical theory but is nowhere near the powerhouse Starlight thought he was and he was too embarrassed to admit that to her.