"In poker, you can play perfectly and still lose."

Only true over the short term: all you have to do is play GTO poker over an infinite number of hands in a rake free game and you should at least break even I think!

That said, this fact is the main reason that the game of poker really "works". If playing perfectly (or at least at a much higher level than your opponents) allowed you to always best your opponents, then you'd quickly find yourself out of opponents. There needs to be enough luck involved to keep losing players coming back to the table (the same reason most casino games have a thin house edge).

Poker can be an absolutely soul crushing game to play professionally. "Running bad" where you lose money over 10's or 100's of thousands of hands even while playing well can make you seriously question your sanity. It can also cause you to add subtle (or not so subtle) errors into your game (e.g. playing too cautiously or aggressively) which can turn your once winning game into a losing game, making it tough to decide whether you are currently a winning player running bad, or actually a losing player.

I was a professional poker player in another life and I agree; learning not to be result-orientated is one of the biggest life-lessons it thought me. Deciding to flip a coin for money where you get paid 3x your bet if you win, as long as you can afford to lose half of the time, is correct, regardless of outcome.

The other one is not being afraid of "tough" decisions - often, decisions are tough because all options are close in value. The closer their value is, the less it matters to choose the "correct" path, keeping in mind the future is unknowable and we always have imperfect information.

Yeah, that's a really fundamental and important insight.

The way I like to think about it is that whenever you face uncertainty, your actions might seemingly be proven wrong in retrospect, but may still have been correct based on your past knowledge.

That's undoubtedly correct, but I find it sometimes difficult to apply, since there's always the possibility that you could have overlooked important information, or that you are using that logic as an excuse. In poker, different from real life, you always know exactly what you know and what you don't know.

In one sense, if you have overlooked important information, then you don't have it. And looking for overlooked information is itself an action, with costs and benefits that you need to evaluate with your current information.

I like this comment and I learned the same lessons from golf and poker. Pay attention to the process and what you can control. As long as you make emotionless decisions and execute the process you shouldn't worry about the outcome. In fact the pressure of competing comes from the expectations you put on yourself by worrying about the outcome before you finish executing the process.

The problem here is, in professional poker, the long run might never come.

In online poker, every hand you play is tracked and can be analysed and people have "run bad" over hundreds of thousands of hands; more than a casino-player will ever see in their life at 20 hands per hour.

It should be dependent on your edge no? With tiny edge you can run bad way longer than you can with a big one. And in live-play you should be able to find a table with a huge edge.

Both true, but the point still stands:

You're basically the best player. You'll play maybe 20 hands an hour, live - most of which you'll instantly throw away and make $0. Let's say you play 50% of your hands like a (somehow winning) maniac. That's 10 hands an hour you might make money on. Even the best players' "won money in a hand they put money in" stat is way under 50% - lower, the higher %age of hands they decide play. So you'd expect get 4 winning hands per hour, or 40 hands a day if you have the stamina (and the bad opponents to play with!). Now, most of your winning hands will result in relatively small wins (your opponents also try to win and don't light money on fire) and guess what - the bigger wins and losses stem from the more volatile situations (e.g. going to showdown) where luck plays an even bigger role than in poker in general: It's totally normal to do everything correctly and having to root for a 32% outcome in a big hand.

That long run might never arrive for you, even though you're the best.

I'm not "against poker" by any means, I would not be where I am today without it. Live poker is a (nice) gamble though, not a job.

There is also an interesting life analogy that I like : During a tournament, an often underestimated skill is choosing your table (and thus your opponents).

That skill applies to poker but only to cash games, not tournaments. In a tournament you can't choose your table, it's assigned randomly.