When we were little I told my little sister that her butt was black. This made her cry and she would tell me that she didn't believe me. I would "prove" it by asking her if it wasn't true that her poop was dark. Since she couldn't really get a good look at her little behind (of course *I* wouldn't have suggested a mirror!) I almost succeeded in making her believe it.
A childhood belief about general

others believed things like this
- i used to think that your butt cheeks is where your poop was stored. Anon
- i used to think there were little mini oompa loompas inside of me that pushed the poop out of my buttAnon
- when i was about 5 my sister told me that kiwis were elephant poop— kelli putnam
- My sister once asked her mother why she didn't paint her black....Anon
- For the longest time I didn't know that Spinal Tap wasn't a real group. No wonder I couldn't find their music.— Louis
- Someone told me mascara was made from bat feces. To this day, I'm not sure if it's true.— Schmoopy