I used to believe that their was a disembodied arm (up to the elbow) that used to live in the gap between my and my twin sisters beds.
I thought that if i slept with my arms up outside my covers it would come and tickle me under my arms and wouldn't stop. I imagined it used to move in see-sawing motion....oh it's just too horrible
A childhood belief about under my bed

others believed things like this
- I used to believe that if I farted in bed, a monster would pop out through the covers and tickle me.Anon
- We used to think that if you ran swinging your arms around, you would run faster. — Christine
- that if I flapped my arms hard enough, I could get airborne.— DeQuendre
- When my grandma was little, her dad would tell her that the freckles on her face and arms were fly crap.Anon
- I used to think that 'testicles' was the word for the arms of a squid or an octopus. — Emily
- I used to think that you would get arrested if you didn't swing your arms when you walked in publicAnon