I see it all the time on the net. Some players play, for example, a 15-minute game with a 10-second increment, and they finish the game with more time than what they started with! I've heard players doing this even in OTB tournaments- games that could go on for hours on end.
Is it because they are perhaps too impulsive? (And if so, why not just play bullet?). Or do they like to just use their gut? Is it also a bit an ego thing, as in, "I can beat this guy even if I don't think at all!". Or is it also a part of their strategy, they want to get their opponent in time trouble?
So what are the possible reasons why they play so quick?