[[quoteright:288:[[Film/StarTrekNemesis http://static.tvtropes.org/pmwiki/pub/images/up-star_trek_nemesis.jpg]]]]
[[caption-width-right:288:Apparently Picard's clone forgot that he had hair at that age.]]
Sometimes, [[CharacterDevelopment characters develop over the course of a show]].
And sometimes, [[FlashBack shows will present new scenes from earlier time periods]].
And sometimes, characters in a flashback will exhibit character unlike the way they acted before the time the flashback is occuring.

For example, when [[AliceAndBob Bob]] started on the show in 1991 he was characterized as a JerkAss, but became a JerkWithAHeartOfGold in 1993, and then just became a nice guy by 1995, but is shown in a recent flashback to 1990 to have been a nice guy in 1990, with no explanation/extenuating circumstances.

Usually, this happens unintentionally due to {{Flanderization}} and CharacterizationMarchesOn, often due to the too many flashbacks to track characterization in an ExpansionPackPast. This might be used to RetCon an existing flashback, maybe because it also had to be reshot since it was a FlashbackWithTheOtherDarrin. If you not only pick up your old characterization but also your old visual style, it's a RetrauxFlashback.

Trope name comes from "backporting", a concept in software development where features from a new codebase are imported to an older branch of development.
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!!Examples:

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[[folder:Anime & Manga]]

* In ''OnePiece'' we have Luffy, the straw hat wearing hero. He got the hat, which is his NumberOneDime, as a 7-year-old. At the start of the series, where he is 17, this caused a problem for him because the hat would often fall off in battles so that he would have to make another person hold it for him. After the Alabasta arc, he gets a string strap for it so that he can have it hanging from his neck while fighting which gives him much more flexibility (probably because he was very close at losing the hat in the Alabasta arc). Some time later, we get a flashback to when he was 7 years old, and suddenly, it appears that he already had the string strap back then.
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[[folder:Comics]]

* Judge Anderson, a psychic Judge in the Dreddverse, was a very flippant and easy-going character when she first appeared in ''ComicBook/JudgeDredd'', though would get serious when the situation mandated it. As time went on, [[CharacterDevelopment she became]] a rather serious character most of the time, and her dominant mood was vague despair at the [[CrapsackWorld shape of the world]]. In late 2010, possibly as part of the buildup to the new ''Film/{{Dredd}}'' movie, Alan Grant started writing a {{prequel}} series, ''Cadet Anderson'', set [[ExactlyWhatItSaysOnTheTin during Anderson's days as a cadet]]. In the prequel series, she is a very serious character who wishes the world could be better, in seeming contrast to the fun and light-hearted lady who first fought Judge Death.

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[[folder:Film]]
* In ''Film/StarTrekNemesis'', they show a picture of Jean-Luc Picard when he was young, and for some reason, he was bald, despite the fact that his balding had everything to do with his age, as previously shown in the show. This also makes the villain quite baffling. However, Creator/PatrickStewart himself really ''had'' lost his hair by this age, really muddling things.
** One handwave that swims dangerously close to being a VoodooShark is the fact that both the picture and Shinzon have stubble, indicating both the young picard and his clone shaved their heads on purpose. Other flashback Picards with hair had just let it grow back.
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[[folder:Live Action TV]]
* Averted in ''Series/{{Lost}}'', which cuts around with its flashbacks, but keeps characterization as established when the scene takes place (noticeably when Shannon and Boone are shown shortly around the time of the crash, Shannon is still doing nothing but complaining.)
* Series VII of ''Series/RedDwarf'' contains flashbacks to shortly after the revival of Rimmer (Series I). The style of the 'H' on his head and his uniform were the ones from Series VII.
** Kryten's [[TheOtherDarrin changed appearance]] is handwaved by the explanation that Lister rebuilt him after a spacebike crash, yet a few episodes later we see a moving photograph of Kryten pre-crash and he looks ([[CanadaEh and speaks]]) the same as post-crash. Additionally, the other Series 4000 mechanoid we meet, Able, looks like the "rebuilt" Kryten as do his spare heads in "DNA" and "Beyond a Joke".
** The flashback in series 2's "Stasis Leak" to before the accident maintains the set design and props that were added to the bunk room in series 2.
* ''MyNameIsEarl'' had this twice, both with heavy lampshades. Two flashbacks saw Earl being the good guy despite the show's entire premise being he was an awful person until he "discovered" Karma. One featured Earl saving Joy from a killer bee while his [[TheAce cousin]] cowered in a tent, and the other was his [[RetCon reasoning]] for [[AuthorsSavingThrow raising two kids who were not his own]]. Both were described, if memory serves, as the only good thing he did before he made the list.
* ''Series/StarTrekTheNextGeneration'' had this in the series finale. The captain's chair shown in the past is the same one as the then-current chair, with little lights under the arm-rests instead of the folding panels the first season chair had.
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[[folder:Video Games]]
* In ''VideoGame/SonicAdventure2'', there are numerous cutscenes which show one of the characters fifty years ago. Throughout the game, he acquires numerous bits of equipment, and the items you've got are visible on his character model even in the flashback cutscenes.
** The first ''VideoGame/SonicAdventure'' game has a flashback to ''[[VideoGame/SonicTheHedgehogCD Sonic CD]]'', where Amy lacks her signature uniform. They apparently didn't feel like making another model for a few seconds worth of footage.
** A very minor instance occurs with Classic Tails and Classic Dr. Ivo "Eggman" Robotnik in ''VideoGame/SonicGenerations'', in which they are voiced by their current incarnations' actors. This isn't too much of a Backported Development considering they never spoke in the old games at all, but it does mean that throughout his life, Eggman went from sounding like Mike Pollock to sounding like Deem Bristow... and then back to sounding like Mike Pollock again.
*** This is a justified example, however, due to Bristow passing away almost five years prior.
* [[SoulSeries Soul Calibur: Broken Destiny]]'s version of Yoshimitsu strongly resembles his {{Tekken}} 6 appearance, where he looks like an alien rather than a samurai which is what he's supposed to be in the Soul Series (it takes place centuries earlier). In the first Tekken, Yoshimitsu looks more like a knight, which is more consistent with how he would have looked when the Soul Series is set.
* Averted in ''VideoGame/CrisisCore: VideoGame/FinalFantasyVII'', where despite having undergone {{Flanderization}} in sequels and spinoffs, Cloud acts really close to his original characterisation (or at least as close as you'd reasonably expect considering how much younger he is). Aeris also returns to being [[PluckyGirl bossy and intelligent]] rather than being IncorruptiblePurePureness and Yuffie goes back to being sneaky, sarcastic and manipulative rather than a goofy GenkiGirl.
* ''VideoGame/{{Portal 2}}'' changes the design on many items such as the elevators and the Material Emancipation Grills, yet when you return to destroyed areas from the first game they are fitted with the new design. Visiting "Old Aperture" later on reveals that these new designs were apparently in use in test chambers from decades before the first game took place.
** The devs specifically avoided this with the [[spoiler:original, burn-marked but intact CompanionCube though.]]
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[[folder:Web Comics]]
* This happens in ''MSPaintMasterpieces'', where Ferretvision and current strips contradict eachother. In this case, though, it's a conscious retcon.
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