You see that person that gambled and won to save his mother's life and after which he stopped gambling, he will definitely become successful in life because for someone to be that disciplined even after seeing the beauty side of what he preached against, he definitely can't allow the sweeter side of things deceive him because it takes someone who is so disciplined to quit gambling after getting your first win, most people will eventually continue gambling until they encounter the ugly side of it. Gambling is not bad if you follow it with good approach and never allow your feelings to control how you go about it. Be very intentional so that you don't get to regret after your actions.
This sounds so funny attributing a one time even to a life success, i mean, one will not succeed in life only because they made a decision one time that salvaged a situation, life success has got many factors tied around it and cannot be seen that myopically. I understand that singular act has made you see this person to be an epitome of discipline but that isn't all that is needed to succeed in life so that wasn't a sure bet he or she was going to succeed or is the person completely discipline, they may have their own area of indiscipline which they may be battling with outside gambling.