History Main / MistakenAge

* ''Webcomic/{{Beloved}}'' starts with the protagonist finding out she slept with a sixteen year old girl she met at a bar.

* ''Literature/DorothyMustDie'': Mombi is often referred to as an old witch this is accurate-ish in the main series but it's a severe case of [[YoungerThanTheyLook Younger Than They Look]] in Queen of Oz when she is referred to as an old witch despite being in her 30s-40s.

* In the ''WesternAnimation/StevenUniverse'' episode appropriately titled "Steven's Birthday", 12-year-old Connie (and the audience) is shocked to learn that Steven is turning 14, having assumed that he's at least a year younger than her due to his short stature and childish behavior. The characters wonder if Steven's HalfHumanHybrid nature has affected his natural growth, making him looked like this since he was eight, then speculate if he will age any more than he already has.

* It's a running gag in the ''LightNovel/{{Baccano}}'' light novels that, despite nearly half the cast being immortal, only Firo (already [[OlderThanTheyLook a bit young-looking]] before immortality) has to deal with the annoyances of not looking his age, such as getting carded at age ninety, being detained for claiming he was seventy on his passport, and constantly being called 'babyface'.

* In ''Manga/UzakiChanWantsToHangOut'', this happens when [[OlderThanTheyLook the 19-year-old Hana Uzaki]] meets her friend Shinichi Sakurai's boss for the first time. He initially assumes Hana's a middle school student, [[HeightAngst much to her indignation]], and disbelieves he misread her. A quick look down does convince him she's an adult, though.

* In ''Manga/UzakiChanWantsToHangOut'', this happens when [[OlderThanTheyLook the 19-year-old Hana Uzaki]] meets her friend Shinichi Sakurai's boss for the first time. He initially assumes Hana's a middle school student, [[HeightAngst much to her indignation]], and disbelieves he misread her. A quick look [[GagBoobs down]] does convince him she's an adult, though.

* In ''[[https://archiveofourown.org/works/17401478/chapters/42427079 What You Knead]]'', due to Kakashi’s gray hair and him having spent the last few years in semi-retirement, Sasuke and Sakura assume he’s at least middle-aged. When he tells Sakura he’s twenty-seven, she’s so embarrassed she practically runs out of the room.

* In the ''WesternAnimation/StevenUniverse'' episode appropriately titled "Steven's Birthday", 12-year-old Connie (and the audience) is shocked to learn that Steven is turning 14, having assumed that he's at least a year younger than her due to his short stature and childish behavior; Steven's HalfHumanHybrid genes has affected his natural growth, and he has looked like this since he was eight.

[[caption-width-right:340:"Oh, [[AndImTheQueenOfSheba and I'm the president of the USA]]." "Wait, [[EasilyElected how]]?!"]]

%% Image removed per Image Pickin' thread: https://tvtropes.org/pmwiki/posts.php?discussion=1481019642044732200
%% Please see thread to discuss a new image.

* In the ''VideoGame/{{Splatoon}}'' fic ''Fanfic/HerFracturedSpirit'', Callie is older than Marie. Everyone thinks it's the other way around because Marie is so mature and aloof while Callie is so free-spirited and exuberant.

[[folder:Film]]

Compare VagueAge, ExpectingSomeoneTaller, ActuallyThatsMyAssistant, OlderThanTheyLook, YoungerThanTheyLook, ReallySevenHundredYearsOld, AgeInappropriateDress.

* In ''[[https://archiveofourown.org/works/17401478/chapters/42427079 What You Knead]]'', due to Kakashi’s gray hair and him having spent the last few years being semi-retired, Saskue and Sakura assume he’s in his fifties. When he tells Sakura he’s twenty-seven, she’s so embarrassed, she practically runs out of the room.

* In ''[[https://archiveofourown.org/works/17401478/chapters/42427079 What You Knead]]'', due to Kakashi’s silver hair and having spent the last few years being semi-retired, Saskue and Sakura assume he’s in his fifties. When he tells Sakura he’s twenty-seven, she’s so embarrassed, she runs out of the room.

Compare VagueAge, ExpectingSomeoneTaller, ActuallyThatsMyAssistant, OlderThanTheyLook, YoungerThanTheyLook, ReallySevenHundredYearsOld, and AgeInappropriateDress.

* Mob in the ''Manga/MobPsycho100'' gender swap fanfic ''[[https://www.fanfiction.net/s/13226631/1/Shigeko-Kageyama-AKA-Mob Shigeko Kageyama AKA Mob]]'' because of the fact that as a female Mob carries herself more like an adult than most teenage girls, how quiet she is, and how she is always seen with Reigen, a grown man. Truth in fiction as females are often assumed to be older than they are once puberty hits.

* One of the races in ''VideoGame/FinalFantasyXIV'' is the Padjal, [[HornedHumanoid Horned Humanoids]] gifted with eternal youth. During the Dark Knight story, Sidurgu mistakes E-Sumi-Yan for a boy, but the Conjurer corrects the "young man" that he is several times his age. Indeed, Brother E-Sumi-Yan, according to ''Encyclopedia Eorzea'' is over two hundred years old.

* In ''WesternAnimation/TheLoudHouse'' fanfiction ''Fanfic/TheNightmareHouse'', Lisa, a preschooler, has a nightmare involving being sent back to daycare and put in a diaper. A teddy bear thinks she's a baby.