Emotions is for what we are playing. If you control emotions, you lose a part of pleasure. It would be more correct to control your betting behavior - don`t increase bet or don`t cash out during the game, because your emotions tell you change your first decision. I made such mistakes when tested strategy with small sums. As the result, about the half of such decisions were mistakes - i lost more money than could win without changes.
Today i don`t cares about bets when it`s done. I just feel emotions from the game from my bet, but don`t touch anything.
In gambling you need to be able to control everything and even emotions, because at first you think that you have everything under control, and then when you have lost several bets, you can decide to bet more to win back, because this will be an emotional decision. But gambling can be predictable if you bet so little that it does not cause you great emotions, then you will exclude the reason why you can lose more than you should.