If you can enjoy the game even when you are losing then you have the right mindset and you can start playing. Otherwise you shouldn't even start.
How can anyone enjoy losing?
NBA Players when they lose a game they are not too worried because they still get a fat paycheck, but a gambler who's losing surely won't enjoy it?
Enjoy the game without looking at the result no matter lose or win. That's the main idea of gambling for entertainment purpose only, losing money for gambler who gamble for fun is just like a fee that he should pay for the entertainment. Like other activities where you need to pay something for it, e.g for fishing, you need to spend some money to buy the fishing equipment although there is no guarantee to get a fish. But the fun while fishing worth the money spent for the equipment.