When my brother and I would play shooting games, I always would say that something was metal, so he couldn't hit me when I was behind it, or he couldn't break it, because I thought metal was indestructible. I believed this until my early teens.
A childhood belief about chemistry

others believed things like this
- 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 believe the large metal structure in Paris, France, I thought it was the "Eye Full Tower"— Janet
- When I was about 4 or 5, I used to believe that instead of bones, we had metal pipes. — TL
- I used to believe that water towers were giant metal spiders. Don't ask. — Goatgirl
- I used to believe that there was special metal laid in the motorways that made the cars go faster!!— angela