The psychology of poker is as a substantial part of the game as the math, the reads, and the strategies. Similarly, it is as hard or harder to master as the other parts. It's no small feat to go from thinking about daily results to understanding that poker is just one long session. No small feat.
In many ways and for many people, it's the hardest part. Virtually nobody is completely of the right mindset naturally, and some people are so far from the right midset that they simply shouldn't play the game.
Much has been written on the psychology of poker, and we even have our own psychology forum. Check out the
psychology forum, and there are 2 books I can recommend (becasue I've read them). "The Psychology of Poker" (ironic title, I know
) and "Inside the Poker Mind."
How long did it take me to get the right mindset? Well, put it this way, quite sincerely. My career consists of somewhere around 200k hands (almost all limit). And I'm still working on it.