The moment of awakening came for me a few years back when I promised myself never again to go on tilt. Without boring you with the bad beat details, I had my set of K's cracked by someone slowplaying his set of A's. This was a weak player, that never gave me a clue until the 3rd raise at the river. I lost a nice size pot, and you know what? It really didn't bother me one bit. I mean not an iota. He had the best hand, I lost. period. Since then, I can't remember ever being upset by a losing a strong hand for any reason, under any circumstances. That was my promise to myself and I've kept it ever since.

I would suggest that every player start there. You'd be amazed at how much further your game advances when your level headed. Just my thoughts.