Speaking from experience, you must be careful when you are winning because it comes with a lot of temptation to continue playing. Gambling has a way of giving you money and taking x5 back from you, this might include the money you have worked hard to get. Losing your hard earned money isn't really pleasant and it might ruin you mentally if it happens continually. It's important to take breaks from it when you are winning Because if you keep pushing your luck you might end up losing everything you have won .
Winning comes with a feeling that you may begin to think you have gotten your way around gambling and another attempt could mean your next biggest win which is just ahead that you are very likely to get. So winning is even a point where one should stop at or take a break if abrupt stop would be challenging as that's they best way I think to avoid addiction ahead.
Loosing your money to the casino with the false hopes that you will eventually win it back some day could be a reason why some persons get addicted even before they realize it and then it could turn out too late already as they have already had a good part of their funds sinked into gambling so it will feel like a loosing game backing out.