I had AA and flopped a set of Aces. I had bet a lot pre-flop and someone called me and the flop came 5 8 A. When i hit my set i thought it was over and had it won. I went all in and he called with 69 and of course, he rivers a 7.
That's just horrible poker, puting all your $ in on a gut straight draw. He had to have know he was a big underdog with the A hitting on the flop, and the chances that you hit a boat, quads, or your set holds up are about 92% from the flop on.
It seems that the minority of players play fairly sensibly in the early stages of the tournament although I am sure there are players who would give me an argument on that. However, when the blinds reach 200 it seems that heads go and panic sets in and all kinds of strange unnecessary activities ensue.