I was CONVINCED that under my bed were those creepy aliens from Sesame Street, the Yip Yips. They would come thrugh the walls at night (they COULD go through walls, you know)and had a base set up under my bed whre they would spy on me and take notes about humans. Of course, having a parent check under the bed was useless because they could vanish.
Thank you for traumatizing my childhood, Mr. Henson! ;-)
A childhood belief about aliens

others believed things like this
- I sused to believe dinosaurs lived in my walls.— Joshua
- When I was little I thought that a "wallflower" was a kind of flower that grew on walls.— A. Nonny-Muss
- I believed God lived in a specific crack in one of the walls of my church — Blake
- I once believed that the walls and ceilings were completely jam packed with plumbing and wiring.— David
- That blue cheese was made by scraping mould off bathroom walls. My mother actually told me that.— sandee
- I used to believe that “Emo” was related to Elmo from Sesame Street.Anon