I thought if you stayed in the water (pool, shower, bath etc) too long your hair would turn red like Ariel's from The Little Mermaid.
A childhood belief about water

others believed things like this
- When I was little I thought that if I stayed a long time in the water I would become a mermaid.— Salma
- When I was a kid, I use to believe, when I put salt in my bath water I will turn into a mermaid.— marletha
- I used to believe that if i splashed water on the wall during a bath, the water would turn into spiders— justin
- When I was little, my dad told me that if you pee in the pool the water will turn purpleAnon
- i used to believe that when you sat in the bath to long and got pruny
that the water made you old— Jami - I used to believe if you stayed in water too long your skin would get really wrinkled and stay that way.Anon