Haha, love it. It continues to amaze me how ludicrous we can be in meaningless moments. What I mean is that as silly as it was for you as a teen to give him the finger, it was even more preposterous for him, a grown man, to chase you for miles on behalf of his wounded dignity. He didn't even have a girl to impress.
Lol, so true, mate! Hence now I can look at it from a "fly on the wall" point of view to really see how pointless the whole thing was. :)