From OP theory, it means you are going to have to train your mind to the extent that it should expect nothing back when you are gambling but that in itself is a very big deal because the mind knows that it should expect a reward when you are gambling not that it's paying to have fun.
Well, that is the point. The mind always will want a win, and that is the generally mentality that comes to play when it comes to gambling. However, what is important now is to fine tune that mind, which in some way it is indirectly called mind control and try as much as possible to stay sane so you do not get to let your mind and the impulses that comes with gambling control you in most cases.
As long as you are actually able to put yourself in that mindset that the OP mentioned, I think we will be able to actually have more of sane and less addicted gamblers generally.