It's not technically under my bed but when I was 4 or 5 we lived in a guest house. I was always listening to my parents conversations, and they always seemed to be talking about the 'punters'. I believed the punters were evil people with a leader called Captain Hook who stole little children from their beds in the night. I stayed really still when I heard my heartbeat when I was in bed because I believed it was the punters climbing up a ladder to my window to kidnap me!
A childhood belief about under my bed

others believed things like this
- That captain hook lived in my closet on the very top shelf.Anon
- I used to believe that tv people were tiny famous people that lived inside that box with a window called TV.— Miguel Horacio
- I believed that the ladder on the back of a trailer/rv led up to a swimming pool.— marilese
- I believed travel trailers had a pool on top because the curved ladder was the same.Anon
- I used to believe that the moon lived on top of our house because I could always see it from the window.— Classic NYer
- I used to think an evil spirit type thing called Wango lived in my dog. I was terrified of that dog.— Franklin