I have a bit of money saved up because when I lose my current job (it's a temporary contract) I want to stay at home for a few months and write full time. Also, it will probably take a few months until I'm able to find another job, so I need the savings to survive that long. I'm used to living on a very tight budget, and the only luxury that I allow myself to buy is books, and that's because I pretend that I need them for my future career as a writer (which will never happen, so the money I spend on books isn't really justified).
Also, there was a brief time in my life when I couldn't afford instant ramen, it lasted for about a month, I ate only boiled potatoes, since they are cheaper in my country, and I lost a lot of weight (mostly due to depression, not necessarily to starvation).
I'm very careful about how I spend my money, and I avoid any unnecessary expenses. I don't use, and therefore do not buy, makeup, perfume, jewelry. I wear my clothes until there are holes in them that can no longer be justified as fashionable or sexy. I wear my shoes until there are holes in their soles. I don't own a car and therefore don't spend money on fuel for it or maintenance. I walk for long distances each day so I can spend less money on public transport. But at least I have money saved up for the next time when I'll be in between jobs, and I might be able to afford some writing time when I get there (unlike my co-workers, who might have to start looking for a new job on Christmas day this year).