Outgrowing The Childish Name
A character stops using an immature sounding nickname or shortened version of their name as a sign of maturity
Often times dimunative versions of names are used for children however stop being used as the person ages. If this occurs to a character in-series it's usually either a sign of Character Development or the character trying to seem more mature than they really are. A nickname may end up becoming an Embarrassing Nickname. Compare to Meaningful Rename.
- X-Men: In the "Days of Future Past" storyline, the future Kitty Pryde goes by "Kate" and sees the nickname "Kitty" as a relic of her childhood.
- In the To Kill a Mockingbird sequel, Go Set a Watchman (which was actually written before the prequel and thus has much Early Installment Weirdness to the point where it's considered an Alternate Universe book), Scout no longer goes by her tomboyish childhood nickname. She goes by "Jean Louise".
- Subverted with Ravenpaw in Warrior Cats. He fled ThunderClan not soon after becoming an apprentice, when he was still the cat equivalent of a teenager. He never became a warrior and thus never received his 'adult name' (all apprentices are called "[x]paw"). Ravenpaw however continued to use that name even after becoming a loner.
- Billy the Werewolf is a recurring character in The Dresden Files from the second book onward. He enters the story as a teenager who gains shapeshifting powers with his friends, the Alphas. As time goes on, Billy begins going by "Will", which the Alphas also call him. It's a significant turning point in his and Harry's relationship when Harry finally shifts from "Billy" to "Will" himself.
- The belief in this is used as a sign of immaturity in Otherwise Known as Sheila the Great, where the image-obsessed Sheila hates the fact that her father goes by "Buzz" and tries to convince him to go back to "Bertram," even though even she admits to preferring "Buzz."
- In the Little Women series of books nicknames were needed for the twins John Brooke, Jr. and Margaret Brooke (sharing their parent's names requires the nicknames). Eventually Demi (short for Demijohn, he's half a John) and Daisy (a common nickname for Margaret) were chosen to fulfill Theme Twin Naming requirements. Upon reaching adulthood Demi went back to John (his father being dead by this point prevents confusion), but Daisy remains Daisy.
- Jimmy Olsen in Supergirl is presented several years older than he usually is and is far more mature than most depictions. He goes by "James" instead of "Jimmy".
- The Suite Life of Zack and Cody: In "Super Twins", a wish on a star turns Zack and Cody into superheroes, and Mr. Moseby into a supervillain; at one point, Moseby turns Bob into a suit-wearing adult who prefers to be called Robert.
- Implied in an episode of Law & Order: SVU, when Stabler asks about his son by a nickname, and his wife tells him that he hasn't been called that for years (making it clear how little time he spends with him).
- In episode 3453 of Sesame Street, Baby Bear decides to change his name to "Not-a-Baby Bear", because he isn't a baby anymore and doesn't want his friends to get the wrong impression. He soon finds out the disadvantages of changing his name, such as not getting a package of instant porridge from his Grandma, and how different his fairy tale, "Goldilocks and The Three Bears" sounds. He soon learns from his friends that your name doesn't always have to mean what you are, and that Papa Bear went through a similar experience in his childhood, as his name was also "Baby Bear" once. These convince Baby Bear to be proud of his original name.
- Kenta from No Need for Bushido at one point gets mocked for having "a baby name" but this turns out to have a tragic origin, since his entire clan was wiped out when he was a child so he was never able to receive a "proper" adult name. It symbolizes how he's never moved on from the tragedy and how it's stunted his emotional maturity.
- In Alice Isn't Dead, the episode "The Factory" has the narrator enter the titular factory and meet a young man named Jackie, except every time she loses sight of him and finds him again he grows several years older, and when she addresses him as "Jackie" after he becomes middle aged he requests to be called "Jack" instead.
- In the Foster's Home for Imaginary Friends episode "The Bride To Beat", Bloo fears that Mac is outgrowing him and decides to act like an adult. This includes changing his name from "Bloo" (short for "Blooregard") to "Bob".
- SpongeBob SquarePants:
- In an episode where SpongeBob begins wearing longer pants, and thus seems more like a mature adult rather than a Man Child, his sophisticated peers begin referring to him as "SpongeRobert".
- In another episode, Barnacle Boy does a Face–Heel Turn because Mermaid Man keeps treating him like a kid, despite both of them being elderly, and demands to be known as Barnacle Man.
- There's a woodchuck character on Animaniacs who wants to be taken seriously as an actor and insists on being called Charleston instead of the Embarrassing Nickname Baynarts.
- The Flintstones: Whenever Fred tries to act sophisticated, he tends to calls himself and Barney "Frederick" and "Bernard".
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