I certainly hope nobody finds this racially offensive. As a child, I thought that black people had pink poo.
I'd rather not get into the rationale behind that - to this day, I can't figure out why I thought that.
A childhood belief about weeing and pooing

others believed things like this
- When i was a child, i used to believe that when people ate black beans, they became black— Mar'ia Elena
- i knew that if you ate beets your urine would turn pink and i thought if it was pink, then you could drink it.— JP
- I thought pink lemonade came from pink lemons.Anon
- I thought black people were black because they drank chocolate milk. — Shelby
- I'm black, so as a child I used to assume that white people pooped peach the way I pooped brown.— Rick
- I thought that all black people were African-AmericanAnon