My girlfriend (who's 20 yrs old) didn't realise until the other year that trains have wheels. She'd assumed they were somehow hovering.
A childhood belief about trains

others believed things like this
- Phil Collins song "I missed again" - I thought it was "I pis*ed again" - didn't realise he was an alcoholic?!Anon
- I used to think underground trains actually descended into the tunnel, like a rollercoaster.— Natasha
- I used to believe that there were lots of hamsters in the wheels of the car, and that's what made it go.— Jade
- My mom would tell me to stay off the railroad tracks because the trains were silent and super fast.— Roger
- I used to believe that training wheels were the different colored beads on the spokes.— Samantha
- When trains (subways) go underground, my little sister thought that the lights were shooting stars.— Katie