In my opinion, someone gambling for fun understands and accepts that they are likely to lose the money they wager. The money spent is viewed as the price of admission for the entertainment experience, not an investment or a serious attempt to get rich. Losses are seen as part of the game, not a catastrophic event.

That's right. Those people who came to play for the sake of enjoying the game practically don't think about making a profit. It's a secondary factor that they don't pay much attention to. I wish I could join such people, but alas... I can't just play and not look at other moments during the game. My memory remembers everything in detail and it's no longer possible to deceive my mind, but I really want to forget everything and start all over again from scratch.
Most likely yes they already know that gambling will only allow to be used as a place to seek entertainment and not income, they already know that everything that runs based on probability will never make sense to be used as a place to seek income because there is no certainty and guarantee to always be able to achieve victory and that is indeed a fact about how we should treat this activity if we really want to be safe in the long term.
On the other hand, honestly I don't know about what problems you are experiencing so that you can't become a gambler like that even though you already realize that that's the right approach, and from my prediction it seems like maybe you still can't completely eliminate your interest in winning because maybe before you got a pretty big win, but my advice is to try to keep trying.