~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.
This is something i believe that every gambler should already know and be familiar with, but then, lets not forget that this whole facts about the house having the higher edge over the gambler, this on a very large extent depends on the type of games the gambler is playing, personally, i think house edge have nothing to do sports betting - correct me if i am wrong though, but house edge have nothing to do with sports betting, as winning in sports betting, (no matter what the setting of the house be, or how ever it is programmed,) depends solely on the players knowledge of sports and how much luck they have on their side.
So when ever we are discussing this whole facts about the house always being the winner in the long run, we should never fail to always exclude sports betting in the equations cus someone who is very knowledgeable in sports, and always lucky in their predictions, will always beat the house, even though they may still lose some games from time to time.
In this aspect you are absolutely right, I also include myself in that motion, what do you say, sports betting should not be included in the house advantage, the house advantage only lies in its games, in any game of chance that is controlled The casino is where I focus more than anything, for example, to win the 100usd per day in a casino game is something that I see is possible, but if we have a very large balance, for example, having a balance of about $100k, a dice move can be made, I believe that some moves are made in dice and that profit is obtained, it is like in trading, I also believe that it can be done.
Now, taking all this into consideration, we as players who do not have such high balances to play with, it is very difficult to reach those numbers, personally I would not dare, if I were not even trying in trading, it is like a suicidal situation against my balance, now neither in sports betting, because I am not able to bet that much, my bets are always low, it is with little money, I know that here in the forum there are people who play with a large amount of money, it also goes in those who have a lot of money and because the ability is unique to do it.
When I see that there are people who win big, it is because I know that they have lost a large amount of money, when I see that they lose around 100 usd or more, it can give me an idea that they have been struggling to be able to do something big, however, I think that people must be present in all the effort that has to reach a game point, that's why I say, for me to get to do 100 days I am not capable, I think it is not because I am not capable but because I do not have the capacity, I don't think I even Playing with play money, obviously to try something like this, I would do it many times with the demo mode, because it would be irresponsible to do it like that, without even practicing a bit, well, although some of the games are always random, I think I would still have to practice.
when you say every day $100 then the luck is unlimited and I don't believe that lol. 
