Ah, found it..
Life Lessons From Poker
My biggest, and most deeply felt life lesson from poker by far (I'm still trying to learn it) is if you
know something is a losing play, don't do it. It sounds obvious, but I'm amazed how often I catch myself doing dumb stuff. When I ask myself why I'm doing it all I get back is a belligerent shrug. But I'm taming the disobedient teenager inside me, bit by bit.
I suppose that's emotional control, and patience, but I like to think of it in terms of +- EV (Expected Value).