I remember being fairly certain as a preschooler that since trees were living things, they must poop. I assumed they somehow did it when nobody was looking. When I asked my parents about it, they laughed but would neither confirm nor deny the existence of tree poop.
A childhood belief about plants

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
- Until I tried it in 3rd grade, my parents told me that if I ate paper my poop would come out in packages.— The Mailman
- I used to believe that if you had a pee AND a poop at exactly the same time, then you would die— ange
- I used to believe that when you went poop a monster would eat it— Confused till age 7 now 11