When I first rode the train at about 6 years old, my aunt told me they were each named for how much noise they made. For example, the "Q" train stood for "quiet" and the "R" train stood for "rambunctious"
A childhood belief about trains

others believed things like this
- 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 - i used to believe (because my dad told me so) that AM stood for "awful music" and FM stood for "fine music"— skydvgrl
- i used to believe A.D. stood for "after dinosaurs".— Jennifer
- i used to think that shtml stood for
"sh*tmail".— anonymous - I used to believe that whenever I got an F on a test it stood for fantastic. — megan