Here's what can be considered a funny/tongue-in-cheek excerpt from Manrique...
(About being a professional, with special attention to #9)
A Perfect Professional proceeds like this:
1- He never rushes to lose.
2- He never rushes to recover.
3- He never rushes to win.
4- He never rushes to leave.
5- You do not stay in the casino more than the time you need to win.
6- When you are losing, you play less or don't play, or stop playing.
7- When you win, you don't get excited or do calculations about how much you are going to win, you just think about what to do when you start losing.
8- Always, even if he loses, he leaves with something of what he brought.
9- Reads Manrique.