We all know we don't have that luck everyday, so we should choose which game to play that uses skills more than luck so that we still have the control on our game and bet amount if you want to have a long run in gambling.
Seeing gambling as a type of income in general is a big mistake in my opinion.
It is what it is, you play and you might win or lose.
If you always keep that in mind it won't matter when you've made a loss in the long run, because you only played with money which you could afford to lose.
Every gambling certainly has its disadvantages and weaknesses that we can take advantage of to get an advantage in the game. But to find these weaknesses requires quite a lot of experience in order to obtain a good strategy when have known flaws.