I know a man who has never missed a loan payment in his life. Actually, he's never made a loan payment in his life.

He pays cash for his cars, owns his home outright, keeps money in the bank, and doesn't owe anybody anything. He's something of a survivalist. Not the fellow hiding in the woods with seventeen rifles and a year's supply of canned beans. Just a responsible, independent man who believes in being prepared, living within his means, and never depending on somebody else's money.

Then one day he decides to take out a mortgage. The bank looks at his credit history and discovers a problem. There isn't much of one. Apparently, the trouble with never owing anybody money is that nobody knows whether you're any good at owing money.

Ridiculous, isn't it? Well, maybe not entirely.

I've been thinking about this from the lender's side, and there's a question we tend to overlook. Does being good at avoiding debt mean you'll be good at living with it? Our man has spent thirty years enjoying complete control over his money. If he wants to buy something, he buys it. If he doesn't have the cash, he waits. Nobody takes a piece of his paycheck every month.

Now imagine him making a mortgage payment for the next twenty or thirty years. Every month, without exception. That might sound perfectly ordinary to someone who's been paying mortgages, car loans, and credit cards for decades. But to a man who's spent his entire life avoiding financial obligations, it might feel like a slow hemorrhage.

Will he accept it? Will he resent it? Will he start questioning the wisdom of borrowing every time the payment comes due? And if business slows down, will he treat that mortgage as a sacred obligation or as an intolerable intrusion into the independence he's spent his life building?

I don't know. Neither does the bank.

Of course, a thin credit file doesn't mean someone has a bad credit score. And a man with substantial assets, steady income, and a history of financial discipline may be an excellent borrower. Lenders have ways to evaluate people without conventional credit histories.

But here's the interesting contradiction. The very habits that make someone financially responsible may leave us knowing remarkably little about how he'll behave when he becomes financially obligated. We've confused two different virtues: the discipline to stay out of debt and the discipline to remain in debt without losing your mind. One doesn't necessarily prove the other.

So here's my question. If someone has spent his entire life proving that he doesn't need to borrow money, should we assume he'll be an excellent borrower? Or is the bank perfectly reasonable to wonder how he'll handle a responsibility he's never had to live with before?