In the year 10 BDC (Before Debit Cards) I had visited a friend in the Midwest. I was living in Atlanta and decided that, rather than paying to park at Hartsfield Airport, I could stretch my meager budget by taking the oft-laughed-at MARTA train. (Motto: "Ride MARTA, it's SMARTA." Laugh all you want, MARTA drops you off inside the airport terminal, unlike NYC, where none of the three airports can say that.)

I'd lived large on the small amount I brought, so large in fact, that I didn't realize I had only 60 cents left. And I still had to buy a token for the train ride home. I opened and reopened every pocket in my purse, every zipper in my wallet in that frantic way when you come to the understanding that, since you don't have magic ruby slippers, you will be stuck in the airport forever like a bad Tom Hanks movie and you don't even have a Russian accent.

MARTA was cash-only, and since this was also the year 5 BCP (Before Cell Phones), my options were limited. I could call a friend collect, but it was late and I already felt lame enough. Since the currency exchange accepted credit cards, I gave serious thought to converting 20 dollars into Japanese yen and then converting it back to dollars to get the cash. (Ingenious, no?) But soon after, a grandfatherly gentleman in a business suit asked if I could use some help and I poured out my pitiful story. He gave me the change and I never forgot his kindness.

It was just last week a woman at Grand Army Plaza had the same anxious and pathetic look on her face. In lieu of ruby slippers, she needed a swipe, but she was going about it all wrong.

Those of us who ride the subway frequently have an unlimited Metrocard. For one monthly fee, you can ride as often as you like. The catch is that you can only swipe your Metrocard once every 15 minutes or so. As with the rules of any program, people quickly learn the loopholes — things not possible with the old token system. Let's say you're an entrepreneur (e.g., you sell batteries in the subway cars). If you pay two dollars to get on the train, you'd probably have to sell five batteries just to break even. Now if you ask someone coming through the turnstiles for a swipe of his unlimited Metrocard, no skin off his back and you're making a profit from battery number one.

But the tired woman standing outside the Grand Army Plaza turnstiles was clearly new at the game, asking people who were on their way to the platform, instead of people on their way out. She said, "Excuse me. Could you…"

Before I realized she was talking to me, I'd already swiped my card and was through the turnstile. No going back then. Waiting 15 minutes to swipe again for her is really beyond my rush-hour benevolence. I looked at her drooping face and did what I thought would help. I pointed to the Chinese lady with the batteries who, speaking no English, had just finagled a swipe from a black teenage girl coming out. The woman nodded, now on the right track.

Moral of the story: Since you don't have ruby slippers, always buy your ticket home before you leave.

Jacquelin Cangro