I used to think that a girl's vagina faced towards the front, and that my penis should point forward. When I started to get erections, I thought my penis was at the wrong angle. I learned the truth from an anatomy textbook.
(Yes, I did wonder how babies came out, as they'd have to turn about 90 degrees if the vagina faced forward).
A childhood belief about rude bits

others believed things like this
- i used to believe that a penis was the same as a vagina except really long— *stupid*
- i used to believe that if you have sex for too long, the penis would stay in your vagina— Angela
- i used to think that having sex was licking the persons vagina or penis until u got tiredAnon
- When I was a little girl, I thought all babies came from 'China' (a Vagina)— Lainie
- 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