My sister used to think that there were two people hiding under her bed, one had really short arms and would try to grab her from the sides of her bed, the other had super long arms but not long enough to grab her from the top and bottom of her bed. As long as she slept right in the middle of her bed, everything would be fine.
A childhood belief about under my bed

others believed things like this
- I used to believe that you could stretch a rat's body to be super long.Anon
- I used to believe that showing my bare arms meant that I was naked, so I never wore short sleeves as a kid. Anon
- I used to think a female daddy-long-legs was called a "mummy-long-legs".Anon
- I used to think Jaywalkers were people who walked briskly whilst swinging their arms.. whoops!— Lisa
- I thought that 1983 went on for 3 years - had to ask my sister who decided how long a year lasted.— Sally
- We told our little sister that she had a long bushy tail and she fully believed us for ages!!Anon