When I was very small I believed that children had no bones and that everything you ate somehow became 'stuck' to hollow spaces inside your body, where the food would become bones.
By the time I was about 3 I thought I had about half my bones and used to visualise things sticking to my half-formed skeleton to make my bones bigger.
I guess this comes from being told 'Eat up to make you strong'...but my poor mother couldn't stop laughing when I asked her about this!
A childhood belief about general

others believed things like this
- My Mum told me that if you swallowed chewing gum, your bones would stick together inside you.— Pauliboy
- Broken bones meant that your arm or leg was separated from your body.— Kelly Hanson
- I used to think that instead of bones and blood and tissue that you body was made up of tuna.— m.n
- My girlfriend believed someone who told her that chewing gum was made from dogs bones!— tony
- I used to believe that when people broke bones, doctors would give them a new part of the body they broke. — Kelly
- When I was little my sister told me salt was ground up dinosaur bones...I barley ate for a month...— Chandler