My father didn't realize I was sitting in the living room when I was age 5. He opened the bathroom door naked, saw me, and sprinted for the bedroom. All I saw were a bunch of fleshy things bobbing up and down. For years I thought that men had 3 penises. I used to wonder if they could only urinate out of one or if they could pick which one to use!
A childhood belief about rude bits

others believed things like this
- I used to think that you could get a tan if you turned the oven on, opened the door and stood in front of it.Anon
- I used to think that women had a secret door on their stomach that babies opened when they were bornAnon
- My father used to call soya sauce "monkey blood". I didn't even consider tasting it for years!— Me
- That there was a zombie living behind the bathtub in the upstairs bathroom.Anon
- When I was a little kid, I believed that erections were caused by the need to urinate.Anon
- I used to believe jaywalking meant walking around naked in public (from naked as a JAY bird...)— Izzi