I used to think that everyone was born without a penis, and the boys grew penises if they were boys. That was up until I had a little brother. :D
A childhood belief about rude bits

others believed things like this
- I used to think that hot dogs were made from boys' penises.— never eating hot dogs again
- 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
- i used to think boys were born from men and girls were born from women— swag lad123
- I used to think that boys didn't get their penis until they were 18 which was legal adulthood! — beckles
- I used to believe that condoms were weared by girls and boys
both. And they both have penisAnon