My parents convinced me when I was little that I once had a tail and that I had gotten it removed. Mostly my mother. We both have a unique personality, but that was just mea.
A childhood belief about general

others believed things like this
- My Dad convinced me that Manx cats had no tail - and only three legs.— Jim
- When I was a child, I used to believe that Catalonia was the unique part of land of the world.Anon
- My mother's name was Anna. She was called "Annemor"(Duck mama). I was convinced I was a duckling.— Christine Norway
- I used to believe that when you had a cousin twice-removed, they had died and came back to life twice.— Amanda
- My mother convinced all of us kids in our family that the large rhubarb in the garden was a Man-Eating Plant. — H.Miller
- I used to believe that if the tyres were removed from a car, it would work perfectly on a railway track.— Anonymous Whistleblower