It is true that this mentality is rare but at the same time it is the most realistic one, as much as I do indeed like to gamble this does not blind me from the truth, over the long term I have no chances at all of earning any money unless I got lucky and won a massive jackpot, and knowing how unlucky I am I know this will never happen, so from the beginning I know that any money I deposit at any casino is money I will never see again and that is why when I suffer some losses I am not really affected by it.
You are right and better to keep that mentality to avoid making big mistake and losses a lot more, there are gamblers who are keen in finding ways to win or recover back the money that they spent playing or betting with the games that they choose, kind of perceptions that may lead you to lose more instead of enjoying the game or your sessions it will add more stress and regrets when the outcome won't turn to your side,.
It's a big mistake when you keep chasing either with a big jackpot or you are trying to win and turn it to the other side and you will try to seek on how to recover instead of calmly playing.
One of the great advantages of thinking like this is precisely that the number of mistakes you will make will go down, as even if you were losing money during your session at a rate faster than expected this will not fluster you and you will remain calm no matter what, and with that state of mind it is going to be very difficult you could make a mistake like chasing your losses, as you will simply accept that was not your lucky day and immediately move on.