I worry about money. I imagine there are some people who absolutely do not worry about money at all, ever, no matter how little they're making or how deeply in debt they are, but I cannot imagine such a life. I need my financial life to be in order or I spend a lot of time worrying about it and feeling uneasy.
For me, the #1 reason to live frugally now is the peace of mind it brings.
If you are not saving any money, if you're living on virtually every cent of your income, you are only one unexpected expense away from disaster. If your car suddenly dies or a child gets sick or you/your spouse gets laid off or your employer gives out pay cuts, or you suddenly owe taxes when you expected a tax return or your roof starts leaking, and you don't have money tucked away, you're in trouble.
If any of those things (or the millions of other things that can go wrong) happen and you have no way at all to pay for them, you're left to suffer the consequences.
When our house's air conditioner had to be completely replaced last summer (to the tune of several thousand dollars), it was unpleasant, of course; I could think of a hundred things I would have rather spent that money on (every last one of them more fun than an air conditioner). But, thankfully, it didn't break the bank for us. We had savings to pay for it in cash and not think about it again. We didn't have to sell our car. We didn't have to put it on our credit card at 100000% interest. We didn't have to live on ramen noodles for six months. We didn't have to ask either of our parents to loan us money. It was inconvenient, but it was not a tragedy, and it didn't put us in a tight situation.
Living within your means, enough that you can have an emergency fund, is the only thing that acts as a buffer between you and unexpected, unwanted financial tragedy. If you do not have savings or an emergency fund to pull you through those events, you'll have to take on debt to cover the expense.
And avoiding debt is the second biggest reason I am willing to live frugally now. Stay tuned!