When I was a child, I was convinced that there was a certain type of criminal who specialized in pushing people in front of on-coming subway cars. I used to ride the subway with my Mom in NYC quite a bit and she was always warning me not to get too close to the yellow line because someone would "push me into the path of the train" -- I didnt realize that she meant that this might happen accidentally. Rather, I believed that every station had armies of "bad guys" looking to toss people in front of trains as they come into the station and that anyone who got too close to the edge of the platform was going down.
A childhood belief about trains

others believed things like this
- I thought the underground railroad was actually a subway.— Greg
- I used to believe that the "no outlet" sign on roads was a warning to people driving electric cars.— c
- As a child i was under the impression that the huge power station chimneys were cloud makers.— scruffyoik
- I was told as a young child that if I didn't smile going past the police station, I wouldbe arrested.Anon
- I used to believe that the yellow sky during a sunset meant that people were peeing a lot.Anon
- I used to believe, driving in front of all the other cars on the highway, Knight Rider was leading the pack.— Michael Kolassa