This is the problem of gamblers as they always have that positive thoughts to win the game. Some gamblers goes as far as not giving up in their gambling activities when they have the opportunity to quit after a good win. They will believe that since the game is in their favour that they should continue playing and they forget that they might not be lucky in the next game. This pushes them into betting more than quitting because of the greed of winning more,which ends up into a great loss because what they have won will be taken away from them. Greed is the road to big loss.
Gamblers are very susceptible to fall into the appropriately named Gambler's fallacy, in which they believe that just because they have been winning recently then this is going to keep being the case, when in the majority of the gambling games what happened on the past does not matter at all when it comes to the upcoming bets, an example of this is the roulette in which even if the red color has appeared 5 times in a row, it does not change at all the odds of the red color appearing during the next spin of the roulette.