Rule 20: Concentrate on how you are playing, not on whether you are winning.

I he idea of winning money, as we have seen, is a false goal. You can
actually be playing quite poorly and be winning quite handily. This is not the
victory it feels like, however, for eventually this bad play will catch up to
you. And while it might be momentarily pleasing to win money, it is
disastrous if you are achieving this by playing wrong. (Probably the thing we
should hope for is to lose when we are playing wrong, for this will steer us
toward the correct path.)
Money, as a measure of poker expertise, is quite unreliable. Here is an
example. Suppose you are winning $200 in a poker game. Going by this
measure alone, this would mean you've been playing very good poker
indeed. But suppose a better player, dealt the same cards as you've been
getting, would be up $600? Now a different picture emerges. We see by this
example that money alone is not a good measure of poker play.
You should go home from a poker game on some nights losing $250
and be proud of the way you played. And you should go home on other
nights a $300 winner and be disgusted at the way you played.
Be as proud of yourself for playing well with bad cards as you are for
playing well and winning. Achieve your sense of satisfaction by this path
also. Actually he proud of yourself for doing this.
The process must always be kept uppermost, because it is what will
win you money over the long run. Give yourself a pat on the back every time
you make a correct play, not every time you rake in a pot.