As a kid I was often taken to the train station to watch the trains come and go. I observed how the switchmen operated the switches to send trains down one track or another. In this case, they pulled up a lever to change a switch, and the lever seemed to block the "wrong" track, that is the one the train wasn't supposed to go proceed on. I got the idea that that was how the switches worked, blocking the wrong track, so if a train started down the wrong track, it would hit the lever, bounce back, repeatedly if necessary, until it happened to go down the right track, the one not blocked by any lever.
A childhood belief about trains

others believed things like this
- I used to believe that if the tyres were removed from a car, it would work perfectly on a railway track.— Anonymous Whistleblower
- I used to think that the laugh track on sitcoms were the camera men, directors, other actors, ect. laughing.Anon
- i used to believe that if you put a penny on a train tracks that it would derail it — ROSS
- For some reason, I used to believe that women only got raped on train tracks.
— Jessica Tinch - When I was little my sister told me that if I put a C.D. in the wrong case, it would mess up the C.D.'s songs.— Torrie
- The sun switches off at night and on again in the morning — Edward