When you reach your goal, that's the time when you should alert yourself to stop because greed rings up your mind and you should know how to cut the call, else you might gamble again and lose what you already had.
to reach goal? no it is not possible to reach the goal what the gamble have kept for themselves. the gamblers have the goals to become the richest person to earn a highest amount with their gambling which you may know is not possible if you are only a player and you may know they often come to stop when they remain with nothing.
Gambling prey on the weakness of the human mind. When the gambler is winning, he will believe that he may be able to win more since he is winning. So he will end up playing even more and maybe even bigger. On the other hand, when he is losing, he will believe that the worst maybe going to be over soon and his luck is coming anytime. So he will keep betting. Either way, this will cause him to lose due to house edge.