Consider, for a second, the debit card. If yours is anything like mine, it’s a battered, unimpressive piece of plastic with some numbers on the front, and a signature on the back that’s nearly worn off. I suspect most of us think about it when we lose it, and the hassle involved with canceling it, eliminating fraudulent charges, and getting a new one.

But a debit card is more than that. By itself it’s a piece of plastic, but if it’s backed by a multi-billion dollar payment network in every store in the developed world, it’s the equivalent of carrying around your entire bank account. It’s access to whatever purchase, in cash, that you want at any time. No need to worry about going into debt with a credit card, carrying cash, going to an ATM, remembering the checkbook, etc.