If you have a bank account or a car, you can never use all your money or all your fuel. If you spend all your money or use all your fuel, you will be fucked.
I have lived for over a week with less than 0 in my account in college and I've driven my car 150km with the gas light blinking in panic. Your argument is invalid.
Because some people don't have cars. And some people don't have bank accounts. That's why I said "or."
I have that shower thought frequently whenever I realize my bank account is down to the triple digits so that means I can't spend any money just in case because it's always necessary to keep money in the bank due to unforeseen circumstances, which always happen. And also there are a lot of things I'm saving up for so I just can't spend any money at all. And I'm like "What the heck? I earned this money. But I can't spend it."
Same with fuel. You can't have zero gas in your tank ever. Or you will be driving down the freeway one day and run out of gas and that will be a problem.
Sounds like someone with very little life experience. You can absolutely do all these things. You can also give money to a relative or spouse for safekeeping while your account gets drained. Whatever floats your boat. Having a self imposed number from which to not touch your money is your choice and its both fine to do or not to do it. Being condescending about it is the problem.
I've finally gotten out of hitting single digits every month, and it's nice to finally not have to micromanage the order my bills are paid to not overdraft