When I was in nursery school (pre-k), we would often take class walks around the neighborhood (to the park, "big" schools, etc.) Whenever there was dog poop on the sidewalk, the teachers would yell "single file! single file!" so we would stop holding hands and could clear the dog poop. For at least 2 years after that, I thought "single file" meant dog poop, and I would shout it out, like the teachers, whenever I saw some.
A childhood belief about weeing and pooing

others believed things like this
- I actually asked my mother if mixing girls' poop and boys' poop would cause an explosion.— kraine
- My poop was always around the same color as my skin so I assumed white people's poop was white.— jaycee
- when I was little I used to think that white people had pink poop (i am brown so my poop is brown)— helena muteka
- I thought the lyrics to "Single Ladies" were "If you liked it, then you should've put your name on it."Anon
- I believed that our teachers lived at school. They were teachers--they had no reason to leave :)(Anon
- I used to believe that God was like a puppeteer, controlling every single movement we made. — Carrie C. in PA