One morning upon waking up in my parent's bed (I was about 2), I gleefully pulled my pants down and showed my mother my penis.
"That's my penis! Show me yours!"
I was nearly catatonic when my mother explained to me she didn't have one.
A childhood belief about rude bits

others believed things like this
- I used to think that Frankie Avalon sang, "Hey Penis, Oh, penis..." instead of "Hey Venus."Anon
- I used to believe that gay sex involved a man sticking his penis inside another man's penis.Anon
- I used to believe that gay guys had sex by sticking their penis in the other's penis.— Fanbrat
- I thought that the show Beavis and Butthead was called Penis and Butthead.— Porky's Butthole
- I used to think that boys didn't get their penis until they were 18 which was legal adulthood! — beckles
- I used to think that men's poo came out of their penis' like wee.— Helen