I was informed by my mother when i was young that if I scrubbed my belly button too hard in the bath, it would 'untie''. Until about the age of 12 I was wary of this situation.
A childhood belief about belly buttons

others believed things like this
- when i was young i was told that if i played with or turned my belly button that my bum would fall off — lee hull
- I used to think that if i touched my belly button it would unfold and my belly would be inside out forever. Anon
- babies come out of your belly button— Kit
- when I was a kid I thought that babies come out of a belly-button.— Ana
- When I was a kid my dad told me that if you unscrewed your belly button your bum would fall off.— Ann
- I was told that your belly button is where you put salt when you eat apples in bed.— Shurnuff