I used to think that the girls' toilets at my primary school were haunted, so I set up my own Ghostbusters' club with my friends.
We also used to think that this teacher (who was, to be fair, a complete bitch) was really an alien with green skin underneath her human disguise. (I think I got that from watching Roald Dahl's "The witches")
Funny though, we never caught any ghosts, only a haunting stench.
A childhood belief about teachers

others believed things like this
- I used to think that girls' anuses were green. I remember thinking that as late as high school.— Jack
- I used to think that green poop ment you were an alien.— fartcheeks
- I used to belive that my teacher was a alien unfortunately this was true mum and said. — peter
- I used to think you had to be in a special club to get a Club Sandwich.— Louis
- Atomatic toilets had people inside of them watching to see when you are done.Anon
- I thought if you get gangrene your skin turns green— Cyberdemon