I remember watching George of the Jungle with my older cousin (a girl) when I (a boy) was very young, and I asked her why George had boobs. She hesitated for a moment, then told me it was because he had long hair. For years I believed that I could grow boobs by growing my hair out. Of course, I never wanted to 'cause then I'd be a girl!
I also, like many other young boys, believed that girls had penises too.
A childhood belief about rude bits

others believed things like this
- When my brother was little, he believed that girls peed out of their boobs.— Emily
- when i was about 4 or 5, i believed that if i pulled on my nipples, i'd grow up and have big boobs.
— JW - I believed that if you ate a piece of your own hair, a new strand of hair would grow on your head.— Ryo
- When I was a little girl, I believed that all cats were girls and all dogs were boys. :)— Mary Ellen
- I thought Buckwheat from "The Little Rascals" (1994) was a girl because he had long hair!— Molly
- WHEN I WAS LITTLE I USED TO THINK THAT GIRLS GET BOOBS BY ONE DAY GOING TO SLEEP AND IT JUST HAPPENS— J.C