My cousin Tiffany is a good bit younger than I. As a very young child she learned the word Mildew, but was confused about its meaning. One time, while she still needed help with going to the potty, she said "I'm about to mildew in my pants!" On helping her to the potty I found that she was using "mildew" to mean "poopoo" or "doodoo".
A childhood belief about weeing and pooing

others believed things like this
- I used to think people had a "potty mouth" if they had been drinking out of the toilet.Anon
- My brother used to be scared to poop in the potty. He thought that he was pooping out his bones.— Lillyth
- that bathroom tap water was recycled "potty" water from the toliet. — livingdeadgirl
- As a small child I believed that the word was "nakeup", finally I found out that it was actually "makeup".— Hannnah P.
- When I was young, I heard the word 'minion' for the first time and thought it was a miniature onion.— Karin
- As a small child I always confused someone being unconcious with someone being dead.— Rick