It's called day dreaming and financially irresponsible. How can they be so sure of something that mostly depends on the luck and nothing else, for me it's hard to understand though.
If I was him I would cashed out 10/10 times even if it's just one game away and definitely I am not going to spend money that I don't have with me even though I am sure it's gonna be there in the future which is the right way of doing it and being responsible while mitigate any pitfalls and many other consequences comes with being broke.
Daydreaming is literally like a dream because there is no action taken, so there is also no result or success on it but in betting we have a chance to win, therefore I won't consider it as one or like that, also, I won't say financially irresponsible if the amounts that we are using are only within our capacity. It is not that they are saying there is a guarantee because they know that this is gambling but it is just that they are also thinking about the what if's, i.e what if I win?
What will I do with the money, or how will I spend it all, etc... something like that. This is not hard to understand but it only takes a common sense on why someone are like that. They are only a human and as a human they have desires too like you and me.
Cashing out early or if the game is not yet finished won't give you a full profit, so that's not what we can say 10/10 but maybe 9/10 if there is one game away but that was still a safe choice as we know a lot of gamblers got screwed by the last game. If there is no money beside you, definitely you can't spend but I remember there is still things like credits which allows you of doing that. Another thing that ensures us a money is if we have a job, or something that are outside betting.
