Learning how the game works is the easy part… readily available for free on the internet or for cheap at the bookstore.
The “discipline” to apply that knowledge under actual playing conditions… all the while faced with a never-ending barrage of temptations to do otherwise… is the hard part.
In fact, the “discipline” required is so other-worldly that the vast majority of low-limit players simply cannot do it. They are so irresistibly addicted to action that they cannot help but gamble… again and again and again.
The only way to rise above the vast herd of gamblers is to train your rational mind to override every emotion that renders you vulnerable to poor decision-making.
Such uncommon self-possession requires more than mastery of the game.
Such self-possession requires you to master yourself.
In other words, the only real opponent you have is YOU!