~snip~
When we have good self-control, things turn out well for us, because if we lose we feel good, since it is something that was likely to happen, there is nothing strange there, but when a person wins and gets excited and feels invincible, You can do very silly things like double the bet to win double, and so on, I think there is no self-control there and it would be wasting the good luck you have had, personally I am honest, I have felt on many occasions that yes, yes. I've lost control a bit, but when I see that I'm losing a lot, I've left it there, I stay with my bad temper, yes, that's agglomeration and I can't help it, and say rude things to myself, but I assume my loss In the same way, sometimes I have two beers, watch a good movie, or why not, go out and eat a pizza with the family to ease the bad feeling, but I get something positive out of the negative, and obviously learning what I don't should I never do so that the same mistake is not repeated, even though I know a lot of things, sometimes one says, well, are we going to risk seeing what comes out? and well, sometimes those risks are not fruitful, but sometimes it is worth doing.
Now I like your friend's attitude, because it is a very calm attitude, it is an attitude that gives importance to him at the moment and that he did not take it into his daily life as a necessity, thus avoiding addiction to gambling altogether, I cannot denying in blackjack you can win a lot of money, and $25 is not bad at all, it is something that I would be proud of, however, these types of people are calm, they do not get carried away by things that are bad, but they themselves They have a discipline for all that, that is what you have to see, and that often goes into the personality, I imagine that when he drinks alcohol, he does not get drunk, because he knows the consequences it brings, it is very good to take things with the best attitude of the world in order not to fall into bad streaks and know when to retire, so it is good to copy some things from others that are positive for us.
The thing is, even if you are calm, and continue to play based on a plan, etc, you will most probably lose it all over time.
That's because the casino has the advantage in all games, called the house edge. Some games will have a large house edge, whereas others will have almost none. Blackjack is one of those games where the house edge is the least. That's usually a good game to play as you will have slightly better chances.
Note that you still have a negative expected return, so if you keep playing, you will eventually lose it all.