When penises were first explained to me as organs which filled with blood during erection, I didn't quite get it. What happened when they were not erect? I figured that penises had to be long empty tubes, and in order to get the rounded bulge that one saw in underwear commercials, men had to manually coil the otherwise flat, limp penis in their pants.
A childhood belief about rude bits

others believed things like this
- I used to believe ghurkins were mouldy penises— bubz
- I used to think that hot dogs were made from boys' penises.— never eating hot dogs again
- When I was younger I thought men had two penises, one for peeing and one for having sex.Anon
- I used to think that women had penises, but that they were just hairier than mens'.— Ameeratron
- When I was about six, I believed that boys had buttons on their penises--one for pee and the other for poop.Anon
- I used to believe both boys and girls had penises so i thought sex was when they tied them together.Anon