When I started to pile some cash, so many opportunities opened up to save more money. Like I've got a chance to buy a good car for a good price, but I need money right now. Or I can buy plenty of food at once with a good discount, but I need to have enough money and enough refrigerator space to store it. Poor people who don't have a house, must spend tremendous money to rent it. I'm spending like $20/month to pay for house that I own. Poor people who don't have a car must spend tremendous money for taxi while I can spend laughable money for gasoline and have cheap transportation (while still keeping the option to use cheaper bus if I want).

Basically when you don't have enough money, you always struggle, you always have to pay more money for basic needs. And when you have some buffer, you often can negotiate and get better deals.

Another example is stress-free life. When I have enough money to cover my expenses for 5 years, I don't really care about being fired, for example. I know that I'll have enough time to find a work. But if one does not have that option, he'll bend before his manager, because he fears to lose work.

Also credits are a bad thing in my book. Mortgage is an exception, but only for cheapest apartments ever, so you can pay it as fast as possible.