I used to think that when people dyed their hair it would continue to grow that color forever. I think I thought this until I was 11 or 12, when I read that someone had dyed their hair red semi-permanently, and I spent days figuring out how that was possible.
A childhood belief about hair

others believed things like this
- I used to think that everybody's hair was black and if you had blond hair, you dyed your hair.— ~_~CoolKid93_~_
- I used to believe that noodles that were dyed different colors such as green had been killed.— Tasha
- I believed that if you ate a piece of your own hair, a new strand of hair would grow on your head.— Ryo
- When I was little, I thought dying your hair would give you the color AND hairstyle displayed on the box. Anon
- When I was little I thought that dying your hair means you kill your hair.Anon
- I used to think that blue was a natural hair color but it as very rare, even rarer than ginger.Anon