Traffic Jam

The funniest thing happens to me in the morning while I am swimming at the Y. I will have someone in front of me that I am trying to pass and they will get to the turn, see me, and then try to swim faster. What is up with that? Why can't they just stop and let me pass? I've noticed that people do that on the highway too. It is one of the strangest of human phenomenons. Is it competition or deer in the headlights? I want to say "If I pass you it does NOT mean I am a better person. In fact, I would put up good money that I am not."