There are some people gamble and lose. if you ask them why do you gamble? They will answer you "just for fun"
They know they are loser in long term and no strategy works, but continue to gamble for fun.
How can enjoy something that you know you will lose? Is losing money really enjoyable? Isn't there any other entertainment you can enjoy?
I think these people are still hopeful of winning back previous losses or they are addicted. Gambling cannot be just for fun. There are many free games too.
Losing money is not enjoyable, but gambling is never about losing only. Even when you are betting with very high odds there is a chance of winning, always. That's where the fun is.
Now, the main mistake addicted gamblers make is that they confuse chance with guarantee. Although you always have a chance of winning, it's never guaranteed. Even when you are betting with 98% win chance, you can lose 3 times in a row and more. That's how they lose big money, thinking "I can't lose again! I'll definitely win this bet or the next one!", and bet again and again until they lose it all. While gamblers who are there for fun think this way after losing: "Well, no luck today. I'll try next time maybe."
In short, there are two kinds of gamblers:
1. Those who can accept their losses and move on, who gamble to enjoy occasional wins, and who never chase their losses. They are there for fun. They are realistic.
2. Those who are there for the money. They are so "cool", they never take a loss. If they lose, they know they must recover and win even more the same day. They are delusional.