When I was young, my mother used to ask us kids if we had done a 'BM'. It was my belief that BM stood for body manure. Horse did horse manure and cows did cow manure, so naturally we did body manure. It wasn't until, I embarassed to say, a hospital stay, that I figured it to be bowel movement.
A childhood belief about weeing and pooing

others believed things like this
- I used to think that "extra body" shampoo meant you could use the runoff suds to clean your body.— Christy
- a donkey is just a small horse.Anon
- I used to think that beer was horse pee. Probably because that's what my mom told me...— Kara
- When I was three I used to believe that cow and horse are wife and husband.— xenia
- I used to think giraffes were a type of horse— Crocotta1
- I was always told that beer was made from horse pee.— Just me