Playing gambling for a long period of time will surely give user a sure loss due to human error. But as I said above, each round result is purely chance.
I looked at the opposite outcome, we are suppose to improve if we play longer, otherwise we are just wasting time and money. I'm referring to particular type of games where you can use your skills, but for luck based games, then you'll surely lose in the long run, not because of an error but because of the house edge, that's very simple to understand.
If you decide to play longer, you will have difficulty controlling yourself as you might see many intension in every round. If you win for some rounds, maybe that will feel excited, but suddenly, you lose for some rounds too, and that can make you have a high intension and of course, curiosity will become bigger.
In this matter, you can get lose control of yourself, and you can not survive in the gambling game. Once you get that, the only way to do it is to stop gambling, no matter if you are win or lose.
That's discipline should be their so instead of losing your control, you'll be more stronger and you'll be able to improve in the long run. Just like getting into business, there are trials at the early stage of your venture but if you learn while you continue, eventually you'll improve.
Maybe treat gambling as a business so you can act professionally.