Because we have experience winning and we are still hoping that one day, we can win again and win back the losses so we continue to gamble even if we know we are already so far in getting back those loses. When we are near of getting it back, we tend to be greedy that instead of winning, we lose being too excited in winning or gamble a large amount to win a large amount as well and not thinking of money management so instead of even having a break-even or a small profit, we just add it to our losses because of emotions.