History Main / DoesntKnowTheirOwnBirthday

* Played for drama in Webcomic/{{Unhinged}} [[spoiler:When Paul starts to heal Erika after her SecretTestofCharacter  ]]she asks him what his age is only for him to admit [[ExactWords that he doesn't know]] and when he told her that he [[SelfMadeOrphan murdered his parent]][[Webcomic/{{Unhinged}} s]] he was just asuming he was around 16 as his birthday was never celebrated and it's not like he can remembered being born. Subverted as Erika proposes to make that day his birthday and promising to celebrated with him the next year.

* Played for drama in Webcomic/{{Unhinged}} [[spoiler:When Paul starts to heal Erika after her SecretTestofCharacter Secret Test of Characte]]asks him what his age is only for him to admit [[ExactWords that he doesn't know]] and when he told her that he [[SelfMadeOrphan murdered his parent]][[Webcomic/{{Unhinged}} s]] he was just asuming he was around 16 as his birthday was never celebrated and it's not like he can remembered being born. Subverted as Erika proposes to make that day his birthday and promising to celebrated with him the next year.

* In the ''Literature/American Girl'' book ''Happy Birthday, Addy!'', Addy tells an elderly neighbor she befriends, M'Dear, that she and her parents don't know her birthday because she was born enslaved and slaves didn't have access to calendars; they only know that she was born in the springtime. M'Dear then suggests (and Addy's parents agree) that she can pick a day around the right time of year and call it her birthday. She spends the whole book trying to find the perfect day and ends up picking April 9th, the day that the North officially wins the Civil War.

* In the ''Literature/{{American Girl|s Collection}}'' book ''Happy Birthday, Addy!'', Addy tells a neighbor she befriends that she and her parents don't know her birthday because she was born in slavery and slaves didn't have access to calendars; they only know that she was born in the spring. The neighbor then suggests (and Addy's parents agree) that she can pick a day around the right time of year and call it her birthday. She ends up picking April 9th, the day that the North officially wins the Civil War.

* ComicBook/XMen: [[Characters/X23SupportingCharacters Honey Badger]] doesn't know her date of birth, being a clone. The Stepford Cuckoos have a similar predicament, but decided to arbitrarily pick a day based on the birth date of their favorite actor.
* In ''ComicBook/SupergirlBeingSuper'', Kara doesn't know her birthday or her exact age. She was a refugee from another planet who suffered amnesia. It's ''assumed'' she's around sixteen.
* In ''ComicBook/AllStarSuperman'', our hero doesn't know when his biological parents' birthdays are, so he's arbitrarily marked two dates six months apart as the days that he'll celebrate them. Since he's the only one observing them[[note]]it's unclear whether [[{{ComicBook/Supergirl}} Kara]] exists in this continuity[[/note]], it doesn't really matter.
* ''ComicBook/TheUnstoppableWasp'': Nadia was raised in the [[ComicBook/BlackWidow Red Room]], and doesn't know when her birthday is. The Champions and Young Avengers end up throwing a birthday party for her when they hear she's never had one.

* An episode of WesternAnimation/WinnieThePooh reveals that Tigger doesn't know what a birthday is, commenting when asked "You were born, weren't you?" "Maybe, I don't think I was around when it happened" and even worrying that he might have been born "someday OTHER than my birthday!". Feeling sorry for Tigger, the others offer to just give him one and HilarityEnsues.

* In ''LightNovel/RebuildWorld'', Akira doesn't know where or when he was born outside of being in the slums, nor had anyone told him the date until he was older. Because of this, he doesn't know his own age or birthday. This is apparently common among slum kids like him.
* ''LightNovel/ReZero'': Felt, an orphan girl living in the slums, doesn't know her birthday and guesses that she's 15.

* Technically the case for anyone who was a [[DoorstopBaby foundling]] (excluding those who had obviously been born the same day they were abandoned); they do have a official birth date but usually it's just an educated guess in order to have something to put on the paper work that's based on how old they're estimated to be when found.
* Tenzing Norgay initially didn't know his birthday, he just knew it was in late May. After climbing Mount Everest with Sir Edmund Hillary he decided to celebrate it on that day, May 29.
* Boxer Sonny Liston did not know precisely when he was born. He believed it was May 8, 1932 and used this as his official date of birth, but researchers have concluded that he was most likely born two years earlier, with July 22, 1930 mooted as one of the most likely dates.
* May occur if someone is born in a remote area that doesn't keep up-to-date on the current Gregorian date because it's not easy to contact or travel to that location. The date the paperwork is physically filed with the nearest administrative office can end up being used as the official birthdate, even if that's several months after the day the baby was actually born.

** {{Implied|Trope}} in ''WesternAnimation/MyGymPartnersAMonkey''. When Adam's animal schoolmates find one of his invitations to a birthday party, they only vaguely understand the concept of the celebration, implying that animals don't keep track of their own birthdays like humans.

* ''WesternAnimation/BobsBurgers'': The premiere episode "Human Flesh" reveals that Bob is so absent-minded about dates he not only forgot Linda's birthday once, but his ''own''.

* ''Series/DarkAngel'': Max and her fellow X5s don't know their own birthdays because they were raised as ChildSoldiers by an evil government project called Manticore that didn't bother celebrating them (although ''The Eyes Only Dossier'' shows that it did make note of them). At the end of the episode "C.R.E.A.M.", Max picks the day before as her birthday in a play on the phrase "born yesterday". Alec is momentarily confused in "Freak Nation" when Normal brings out a cake and starts singing for him, since he had randomly put that date as his birthday on his job application form back when he became Jam Pony messenger.

* ''Series/AgentsOfSHIELD'': Daisy Johnson[=/=]Skye spent her whole childhood frequently changing among foster families without ever knowing her biological parents, therefore she never knew her exact birthday. [[spoiler:When she manages to reunite with them, she learns that she was born on July 2, 1988, not in 1989 as she'd previously believed.]]

* ''Series/TheMusketeers'': Porthos' mother died when he was very young and he grew up alone on the streets. As a result he doesn't know when he was actually born and his "birthday" is just a random date he picked off the calendar so his friends would have a day to celebrate.

* ''VideoGame/IWasATeenageExocolonist'': Since Congruence is an A.I., she doesn't have a birthday in the human sense, but you and Tammy can assign one for her and celebrate with her in an event.

* The titular character of ''WebAnimation/TheLegendOfLuoXiaoHei'' knows for sure that he is "around" ten years old, but he doesn't know when he was born since he's lived alone most of his life. His master Wuxian gave him a birthday, November 5, to celebrate it.

* In ''WesternAnimation/TheWildThornberries,'' [[WildChild Donnie]]'s "birthday" is the date when they found him in the jungle.

* An episode of {Winnie the Pooh}} reveals that Tigger doesn't know what a birthday is, commenting when asked "You were born, weren't you?" "Maybe, I don't think I was around when it happened" and even worrying that he might have been born "someday OTHER than my birthday!". Feeling sorry for Tigger, the others offer to just give him one and [[Hilarity Ensues]].