Many gamblers have said this same thing in the past but all of a sudden they later came back to resume gambling and funny enough this time around was something else. However if you want to stop something for ever you need to mean it because coming back to it shows how weak the person is. Although it takes discipline to stop gambling mostly if it has to do addiction.
The part that I've bolded is the most important one, and that's exactly what it's all about. Not every person can be disciplined enough to leave gambling forever if they weren't disciplined enough to never get addicted in the first place.
That's just it mate. When discipline is not involved it will be very difficult to stop gambling forever. It is even difficult for most gamblers to stop gambling for a while not to talk of stopping it forever. However it is not easy to get rid of what you have started and mostly if money has been involved. Although sometimes greed is the main reason why some gamblers can't get rid of gambling,