I used to believe you knew the sex of a baby (when born) by looking to see if they had hair or not. Girls if born with hair, boys if their born without hair.
A childhood belief about reproduction

others believed things like this
- i used to think boys were born from men and girls were born from women— swag lad123
- I was born brunette with brown eyes and dark hair, i thought people with blue eyes, had water in them.Anon
- 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 I was older than my brother because I was born in June and he was born in OctoberAnon
- I used to hold my hand over my hair whenever i left the house and it was windy incase my hair blew away— lisa
- I used to believe that you could curl your hair by twirling a strand of hair wrapped around your finger— Anonymous