I've a friend of mine who always complain that ever since he started gambling he haven't won a good amount, instead he'll be winning less money than what he expected but he can't stop.
People who gamble and continue losing, but they do not give up on gambling all is because they have hope that one day they will win. No time will a gambler gamble without no hope of winning. So, anything you have hope for, you will hardly give up on it. If any gambler believes they have no probability of winning, they will surely not gamble. It is confidence that always makes gamblers continue gambling. In fact, sometimes, even if they want to give up, the hope that one day they will win keeps them going. They always think that if they stop gambling, they might miss an opportunity.