Actually, I have been drafted once. It was my coworker, who wanted to take it easy on his evening commute (we live in the same neighborhood), because he trains for racing with a cycling team, so it would be counterproductive to ride hard on every commute ride. I didn't mind at all, because if the roles were reversed, I'm sure I would have died. I can't keep up with his true average speed, let alone his top speed.