I used to believe that everybody used to have a tail that grew out of your tailbone, but you got it cut off at birth. Same with shoulder blades-- or, as my mother called them, wing-buds.
A childhood belief about general

others believed things like this
- I used to believe that if you hit your tailbone, a tail could grow out of it.— Ida
- I used to think that the shoulder blades were actually "back breasts".— Kdees
- When we were younger my sister and I used to think that our shoulder blades were really sprouting wings.— Raven
- When i was little i used to think that a birth mark was the place on the body where you came out of the mother— bipbop
- I used to call the shoulder of the road, the elbow.Anon
- At the age of about 5, I thought that any man carrying a bag/sack over his shoulder was a burglar.— Police officer, Ola.