I was always told as a child that the cupboard in the kitchen containing bleach, cleaning fluids and other hazzardous chemicals contained a monster.
However if my parents had told me that there was nothing of interest in there, I wouldn't have constantly tried to find out what the monster looked like.
A childhood belief about monsters

others believed things like this
- I used to believe that when I went to the mountain I would find an ancient monster or find some treasure— Yazer Solorzano
- I used to think that in public toilets, the cleaning lady actually lived in the supply cupboard.Anon
- I thought the boogey monster was a monster that ate boogers at night in front of youAnon
- I Used To Believe The Monster Beverage/Energy Drink Was Monster Milk!— KellGirl
- My mum told me that if you picked your nose and flicked it on the floor then it would turn into a monster!— MadMack
- We were told at school by the evil dinner ladies that apple pips contained arsenic.....Anon