Multiple personalities that can occur when someone is in a depressed situation or vice versa that can make them feel attracted to something. But on the other hand, in my opinion, your friend experienced a change in behavior and mindset because he saw a winning opportunity in gambling, not only your friend because I think cases like this happen and most gamblers experience the same thing, and I will say that people like that are those who are easily provoked by something that looks quite tempting which in the end they try to take advantage of the situation and circumstances, On the other hand when they are in a situation like that then I am sure that they will not consider that it is carelessness especially if at the beginning of the session you are given a win, that's the danger if you are too sure of something that has no certainty.
Well, that what actually happens and there are certain conditions where personality attitudes change instantly if they trigger emotional or psychological pressure which gives certain boost to person mental state.
Similar things often happen and are experienced by anyone, even I myself have experienced the same thing before, when I first felt how happy it was in gambling and experienced series of defeats, there would be phase where I couldn't control what I was doing in gambling.
But as time goes by, if you want to learn and also understand how you should and best gamble then changes like this will never appear again and of course they will remain as they know where to gamble carefully and always avoid carelessness when gamble.
Everything requires experience and learning, so whatever attitude happens will automatically change for the better.
Yes so I think this is a common scenario experienced by gamblers and as I said before that most of them experience the same scenario when they see an opportunity or that means too focused on winning opportunities and obviously changes in mindset, beliefs and behavior will occur, not only that the wrong point of view and understanding makes them experience encouragement when in certain situations, losing and winning situations can change a person's behavior, and it happens more often when they are in a losing situation which ultimately affects mentally and psychologically which ultimately acts under emotional pressure.
You have proven it by experiencing it yourself, not just you because I also admit and I think this scenario applies to all gamblers, sometimes even though we have self-control and boundaries, it's still like you said that there are always times when we are careless because our consciousness starts to weaken which eventually falls and forgets the boundaries we have made before. But on the other hand having a plan for self-control and boundaries is much better than having none at all, because obviously there is a difference in terms of minimizing risk if you have a plan, so self-control, boundaries and awareness should be prioritized when you are involved in gambling.