Greed makes it difficult to stop even if a gambler wanted to stop and pocket the winnings. HIs thought is saying he has to stop but somewhere on the back of his mind there is an urge to just some more tries maybe the next set of spin will give him another good win., until his situation becomes chasing his losses.
They must know when to continue playing or go all in and know when to cash out the winnings they get, if they can't fight the greed that is in them, chances are they will lose everything they have and of course the loss is also sure to feel themselves as well as frustration. They want higher because their satisfaction is still not paid off and the curiosity that exists makes them continue to bet without thinking that the winnings they have got are enough to cash out and enjoy.
Necessary is the skill to know when to "cash out". As wise people, we should have self-control; its not just about the excitement of the bet; its also about having the sense to know when to stop. This is a classic case of "winning the battle but losing the war". Understanding yourself is very important when you're gambling. Fun must be emphasized, but never at the cost of our health.