This one is slightly bizarre, but I used to think
That when you had a haircut and it had to be right below your ears, you had to bring a picture of yourself as a baby, so that they would know what length they had to cut it to, to match the shape of your face. I honestly don't know why.
A childhood belief about hair

others believed things like this
- 'I've got candy in my ears tonight, baby'.
~Canned Heat, Jimiroquai.— Nin - I used to believe that if I cut my dolls hair it would grow back just like mine did after a haircut. — diamond girl
- after my mom told me I had strawberry blonde hair - I used to look for the strawberries after I got a haircut— pearpod
- Even though the title is 'How Bizarre', I always thought he sang "help is on"...Anon
- When I was little I used to believe that if you told a lie, your nose would grow in length. — Lluna
- If you pulled a face, and the clock struck on the hour, your face would stay in that position.— Jo V...NL