Before I came to Japan, I hadn't used money in years. It's not that I didn't have money -- I just never dreamed of taking it out of the bank and using it. That's because on my planet, the United States, money is a thin piece of plastic called a debit card, inside of which are mathematical molecules swirling around constantly rearranging themselves and adjusting your bank balance. I have never understood how a mere 10 digits can represent so little or so much by just changing their positions. Furthermore, how can my bank account balance be negative? Zero is zero, isn't it? When you have no money, how can you have more no money? Even the grammar is wrong.

But that plastic card knows. And plastic has become very intelligent these days, mainly because it has that magnetic strip on the back. If magnetic strips are so smart, why don't we adhere them directly to our own backs?

In the U.S., carrying a lot of cash makes us nervous. After all, it might explode in your pocket. At the very least, you will surely lose it if it's a large amount of money. Yet no one worries about losing their debit card. In the U.S., it's not uncommon for kids to start carrying their parents' credit cards in high school so they don't have to carry cash to go shopping or traveling.