My mom always said that if the guy in the caboose waved at you and you didn't wave back it meant you were not wearing any underpants. Imagine a small child standing there waving like crazy and sometimes there would be no one on the caboose.
A childhood belief about trains

others believed things like this
- I used to think that the upper struture on the caboose was the rest room.Anon
- My dad told me that when he was little, he thought the trees waved back and forth to make the wind blow.— casey
- I thought a tidal wave was acutualy a title wave because if the wave was big enough it had its own title!— Nate
- At a young age I couldn't imagine how people without glasses could marry the ones wearing them. — Ana
- I used to believe that wearing a bra that was too small would make my boobs get smaller.— Aretia
- I used to think that "No standing signs" meant that you weren't allowed to actually stand in the area!Anon