Treating it as spare money for your entertainment will allow you to move forward and accept the outcome, if you lose then quit and stop, if you win then it will add as additional money to treat yourself, gambling always have risk behind knowing and acknowledging whatever the outcome will be your turning point to avoid making mistake the lose more than what you can allow to let go.
Of course, when we only use the amount of money that we can afford to lose to gamble and accept the outcome of the result will help one gamble responsible. This boils down to having self control whenever you are gambling. A lot of gamblers finds it difficult not to think of making profits when they are placing a bet and this can trigger them in using more than the amount of money that they can afford to lose to bet. When they lose their bet, they wouldn't want to let go of their losses.