Usually many people decide in advance that when they win “a lot of money” (without knowing the exact number), they will stop and withdraw this winnings immediately. But when it comes to this, the mind becomes foggy and actions chaotic. The player cannot believe in his success, various thoughts appear that confuse him and he forgets what he wanted to do. He no longer remembers that they need to be taken out as he planned. There must be willpower and a strong character so as not to succumb to the clouding of the mind by this win. My words may not be taken seriously, but that's how it goes when it comes to this, you need to be prepared in advance.
That is a very common psychological trap and I think the reasoning behind deciding against taking the money out that they won is that suddenly they consider money won is some kind of extra money and when they lose it, they haven't actually lost so to say. It is reversed psychology, which essentially makes no sense, but I know that feeling myself. If you win an amount and then lose it afterwards you tell yourself that it is all not that bad as you never owned the money in the first place. But it is a bit off topic now.