I went for a short time as a child beleiving that I should be able to support myself on something I was holding up: take a metal pole, hold it behind your back horizontally, crouch slightly as if sitting on it then try to lift your feet off the ground. Even though I tried and failed, I was convinced I just wasn't doing it right.
A childhood belief about physics

others believed things like this
- I used to believe that the North Pole was the coldest place in the world and the South Pole was the hottest...— Logica
- I used to believe that Metal music was when a bunch of people would bang metal together to make noise. Ha ha.— Kassandra
- When I was a child, I thought that the Heavy Metal was Satanic music.Anon
- I used to belive if someone liftes you up, and you lift them at the same time, you will float in the air.— D'Anthony
- I once believed that one could run around the south pole in order to travel backwards and forwards in time.— kaibutsu
- Since the girls name Jackie is short for Jacqueline, I thought the boys name Jack was short for JackalAnon