I live near the Forth Rail Bridge which has supports that make it look like a Big Dipper roller coaster. When I was younger I used to believe the trains went up and down the humps like a roller coaster and always wondered why they never fell off. When I finally realised my misconception and told my dad, turns out he used to believe the same thing!
A childhood belief about trains

others believed things like this
- i used to belive that if you smashed your hand in a roller your bones would be fine but your arm would be flat— rap masta cheseepuff
- I thought that cars could only make turns when you used the turn signals...— Toby
- I thought that every TV show was filed live, and I always wondered why they never messed up.— Steve
- I used to think that GLASS and GRASS was the same thing. I always wondered why windows weren't green...— Alex
- When I was younger I asked my parents:
"If bees make honey, do flys make marmalade?"— Mike - I used to think underground trains actually descended into the tunnel, like a rollercoaster.— Natasha