The other funny thing some of these aggressive gamblers do is that even if they are lucky to win huge money they will still continue to gamble because they believed that they are still going to win more as they have already won previously. And they still chase loses after losing the money that they where supposed to withdraw. Well, chasing losses and continuing gamble after a big win is an act of greed, if any gambler is not greedy he or she can not do any of those things like chasing loss or plan to win more after winning some money.
When a person allows greed to take over their thinking, it becomes very difficult to convince them they are on the wrong, since once they obtain a huge win, they cannot help to think that if they were to follow your advice then they will deny themselves of all of the potential profits they could get if they kept gambling, so they ignore your advice thinking they know better, and it is only once they lose it all they realize you were right, but at that moment it does not really matter that much anymore.