I used to believe that Mowgli from Disney's The Jungle Book was a girl, because he had long hair just like my sister.
A childhood belief about cartoons

others believed things like this
- I thought Kaa's name from The Jungle Book was spelled "Car" and that he had a brother named Truck.Anon
- I thought Buckwheat from "The Little Rascals" (1994) was a girl because he had long hair!— Molly
- I swear I heard a Disney Channel/Radio Disney song where the chorus was a repeated “Damn it”— SpengBab
- I used to think I could have my hair cut long ...Anon
- I used to believe moustaches were just really long nose hair — RaoulDuke
- My buddy used to think that when Steve Millers sang "Jungle Love" he was actually saying "Chug-a-lug" — Harold