was that guy with a helmet riding back and forth in the lot, by the ball fields? there is a guy that does that all the time. he rides as fast as he can bunny hops across a grass strip between two parking spots, rides up the gravel road then back down jumps a root, then repeats about 30-40 times. its acutally kind of funny.
thought bout telling him to put a helmet on then i realized he's old enough to know better so he's unlikely to take the advice anyway.
if it was a kid, i'd probably pull him aside compliment him/her on his skills, then say, you should ask mom and dad for a helmet, everyone's got one these days.... but this guy has already made up his mind about it I suspect.