I have a friend who spends money like if he doesn't have an even 0 balance at the end of the week, he hasn't done it right.

If he has 50 dollars to buy food, he will spend all 50. If he's going to get a couple of dollars change back, he'll get some Snickers bars to neutralize them. I get that there are situations where you have to live paycheck to paycheck and end up at a 0 balance out of necessity, but this motherfucker lives with his family, doesn't pay rent, doesn't need to buy groceries, doesn't have a car or any recurring expenditures, and has nothing he actually needs to spend money on, he just spends money because he has money to spend.

I get the feeling that if he has some money that isn't being spent he sees it as a wasted resource, like it has all this potential to turn into all the stuff he could be buying with it but that potential is being wasted because it's just sitting around being unused money that he can't use for anything other than spending, and so he spends it. He has attempted to save money in the past. It's never worked.