When I was a kid and my father would fart he would tell me it was a mouse on a motorcycle.
I, of course, would go looking for it.
A childhood belief about farting

others believed things like this
- I used to think that when I moved the mouse around on the mouse pad, I was giving the computer a massage.Anon
- A motorcycle was started by jumping up and down and bouncing on the seat.Anon
- I used to believe that the solid double yellow lines on highways were the motorcycle lane.— jeech
- When I was little and had an ear infection I used to tell my parents I had a mouse in my ear.— Alison
- I used to believe a mouse lemur was a type of a rodent.Anon
- As a child I used to think that the toothy mouse existed.— Jordi Comendador