I did this cool sketch of a young guy sitting across from me. I thought he looked like an artist.
I was trying to look casual, glancing at him every once in a while, but must have been totally obvious, since the woman sitting next to him thought I was drawing her! She got up before getting off the bus and asked to see the sketch. And then she was telling me how wonderful it is to be able to draw, etc., and the usual, "Oh, I wish I could draw, but I can't, just stick figures, etc."
A few minutes after she was gone, my young guy pulled out a sketchbook and started to sketch people on the bus! (So I was right about the artist part...) I showed him the sketch before I got off the bus.
Now, picture a bus where everyone could be busy drawing everyone...