I was thinking of this thread last time I drove our car... and passed a cyclist, and suddenly felt an urge to yell "hey, I'm not really LIKE this, you know! I ride a bike too!!"

But when I'm on a bike I don't really think much about the drivers around me, as long as they give me a little room and don't act aggressively I don't feel the need for any more interaction.

So I was thinking that maybe we want to give drive-by encouragement mostly for our own sakes, because we'd rather be thought of as cyclists than as drivers...