http://www.washingtonpost.com/wp-dyn/content/article/2010/10/01/AR2010100105833_pf.html (one page link; original: http://www.washingtonpost.com/wp-dyn/content/article/2010/10/01/AR2010100105833.html) is a recent Washington Post article on young poker player Steven Silverman. It's interesting.

Even more interesting are his comments and other poker players' comments on Hacker News: http://news.ycombinator.com/item?id=1777385

Some selected comments:

It doesn't matter one jot how well you play at your best, what matters is how well you play when you're stressed and upset and ill and exhausted and it's 2am and the fish whose money you need to take is calling your mother a whore. That's the real job of playing professional poker - you're on a tightrope where an hour of perfect poker earns you $80 but an hour on tilt can lose you $800. The skills that allow you to turn pro are learned as an amateur, but there's a whole other set of skills required to stick it out without losing your mind. I had the former, but not the latter. I walked away from poker because I am absolutely certain it would have killed me.

-- jdietrich, http://news.ycombinator.com/item?id=1778364

Losing streaks are like nothing you can understand until you've been a professional poker player. Imagine if you went to work, performed flawlessly, far better than all of your coworkers, and instead of getting paid your bank account got debited and your boss told you "you really sucked today". Then that happens every day for a month.

Humans (and especially poker players, who study probabilistic decision making as a hobby) are conditioned through life to believe outcomes are a direct result of actions. Do a good job at something and work hard at it, you succeed. Do a bad job at something and slack off, you fail.

While this is true in poker in the long run, the long run can be a long time. I broke even for a year at one point, and that's at cash games. Meanwhile donkeys without the slightest clue what they were doing were lucking ass backward into multimillion-dollar tournament prizes.

You can't even fathom what this does to you emotionally until you've lived through it. It engenders self-doubt, which gets you off your game, which probably makes you play worse, which you know you're doing but aren't sure exactly how, or what to do about it, which in turn prolongs the losing streak. There is no end to it.

-- matmaroon, http://news.ycombinator.com/item?id=1778597

I had a girlfriend for most of that time who went pro. She was pretty good, too, but she had that lack of respect for money in spades (heh). She'd spend a whole day grinding out $3000 in the $40-80 game and then lose $20,000 in an hour at the Pai Gow table.

One day she decided to skip the Pai Gow and went to the mall instead. Bought all kinds of designer clothes and perfumes and electronic gadgets. She practically filled up the car. When she came home there was this shocked look on her face. I asked her what the problem was and she said "Look at all the stuff you can buy for only $5000! I'm so used to using money as ammunition I forgot you can trade it for stuff."

-- tsotha, http://news.ycombinator.com/item?id=1778909

It's strange how poker works but I imagine Buddhism and poker to be the most complementary religion-to-profession complement on the planet.

-- InfinityX0, http://news.ycombinator.com/item?id=1777624

After that I got a lot better, jumped limits, and ended up meeting DeathDonkey in a 100/200 game at Commerce and again realized I was outclassed.

I'd say I owe them a debt of gratitude, but I'm pretty sure I already paid it at the tables.

-- bapadna, http://news.ycombinator.com/item?id=1778094 (included because it is funny)

Wikipedia on 'tilt': http://en.wikipedia.org/wiki/Tilt_%28poker%29

On Isildur1: http://en.wikipedia.org/wiki/Isildur1#Career