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. What I'm trying to say is that discipline comes with nature, and if you were not naturally disciplined before, which was why you got addicted to gambling, you are not going to become disciplined forever, and leaving gambling doesn't always mean that you've changed forever, people often change for sometime, and then they start doing the same things again even though when they are leaving, they behave like they will never return.
Gambling addiction is not that easy to get rid of, someone who gets deep into this once, they spend all their life trying to get rid of the urge that keeps poking them and forcing them to gamble, and this continues even when they leave gambling, or at least pretend to. So, it's not as easy as it may sound, the urge for an addiction is very strong, and even stronger if the addiction is related to money and finances.