You are right. When we have greediness, that will make us get more losses because greediness is a feeling that wants to get more, but we don't know how big our chance to get it. We can stop gambling if we think that is enough to playing gambling.
Being greedy means you have no discipline as a gambler and we know that even if a gambler wins now or tomorrow, he will still lose in the long run if he is greedy, once a gambler is greedy he will always expect a win and would not stop, quit and accept loses, that would put them in bigger risk.
Everyone of us wants to win, but we should be realistic all the time and as long as we understand that losing is possible, we should accept when we lose.