A gambler who doesn't know when they should stop is basically impatient and greedy, and such gamblers barely manage to get something out of their gambling activities because they eventually lose back everything that they might have managed to win during a gambling session. So, practicing patience is a very important thing for a gambler and one should always have enough patience so that they can control themselves when needed.
Our minds will tell us a lot of things but we are not supposed to follow everything it says, and that is where self-control plays its role, if you don't have self-control, you can't get over the urge to gamble more when you've already won something and that will give an advantage to the house.
You need to have that strong will to control your patience, it's natural with our human behavior to follow our emotions, I mean if you feel too much excitement you might forget your set plan, and you will see yourself losing a lot because you forget about your limitations, but along the way you should practice and not to let that emotion to lead you to keep losing your bankroll,
learn when to stop and be contented with what you've got, stop that greediness if you can, it only lead you to lose more money.