When I was around 4 or 5, I thought that traffic lights were changed to red or green by policemen. I thought the policemen were right there at each intersection even though I never saw them - I figured they were just behind a tree or in the bushes or something.
When I saw a "No turn on red" sign, I thought that meant that the policeman working at that intersection was new and kept forgetting and leaving the green light on, so the sign was to remind him, "No, don't just leave the green light on, turn on red." Apparently they never forgot to turn on the green lights.
A childhood belief about traffic lights

others believed things like this
- when i was little thought that ants changed traffic lights from green to red and vice versa.Anon
- i used to believe that red yellow and green meant "ready, set, Go!" on traffic lights..— cabagona
- i used to believe that the green arrows on the traffic lights told you which way you had to go to get home.— Helen
- that the green traffic light turned blue when it was off— Kriket Evens
- i thought that if you sucked yerr thumb long enough it would turn green. dont ask why! — jordan
- My dad could change a traffic light from red to green using our garage door opener.Anon