The money you don't lose from staying too long in a hand and the money another player does lose from doing this is often the profit you go home with. Maybe you got yourself «trapped» a few times on fairly good hands and found yourself staying longer than you wanted, but soon after that you came to your senses and folded. A less experienced player, however, got trapped on some similar hands and stayed until the very end with them.
The money difference in these two cases is often. The difference at the end of the game- the profit the better player goes home with. Profit at lower levels of poker is often nothing more than a matter of getting «paid off» by bad players when the good players have a good hand. (And limiting your own mistakes so you don't give the money back.)
