It's the Friendship Train

Little girl looking out the window: Hey mom, look! Look! There's going to be an express train! Look! Look! You said there were no express trains on the weekends! Look! An express train! There it goes! (pause) Look mom, look! A garbage train! Look!
Mom: Now you know why there's an express train on weekends.

–N Train

Overheard by: Duncan Pflaster