Unlike some of the posts here, I didn't think there were little men or animals operating the traffic lights, I thought the traffic lights were happy when they were green, surprised when they turned yellow and then mad when they were red.
A childhood belief about traffic lights

others believed things like this
- i used to believe that red yellow and green meant "ready, set, Go!" on traffic lights..— cabagona
- I used to believe that the yellow light in traffic-lights meant Go Faster!— M. L. E.
- when i was little thought that ants changed traffic lights from green to red and vice versa.Anon
- i used to believe that the green arrows on the traffic lights told you which way you had to go to get home.— Helen
- I believed that traffic lights had police officers inside them, turning the lights on and off...— CrowHeart
- when i was about 5-8 i used to believe that oompa loompas lived in traffic lights and controlled the lights!!— ~wierd ~