On the return flight home, the woman on my right asked if this had been my first trip to London. It had. She asked if I've seen my own country. I've seen a great deal of it.

"I don't understand why Americans go rushing off to Europe when there's so much to see in their own country," she said, while ordering a double Scotch from the flight attendant.

Beats me, I said, and asked her if she's seen most of Western Europe. (She was on her way to New York to meet a friend who has a cabin in Vermont, her final destination.)

As it turned out, she lived in a suburb just north of London, and she'd been to France and Switzerland, period. And if her husband hadn't been Swiss she might never have left the UK (except to see foliage in Vermont, of course).

Still, I understood her point about Americans not seeing America. I knew a couple from Boston that could negotiate the trains in Italy, apparently no small accomplishment, and yet when they visited me in Colorado, it came as a big surprise that a trip to the Grand Canyon entailed more than an afternoon drive.

It was then that I developed my theory on why Americans would as soon see Athens as Arizona. It has to do a lot with regional biases.

I've learned that, to many Easterners, the West basically is a conglomeration of rectangular-shaped states, notable only for their ski slopes. Conversely, to a lot of Westerners, the East is a stew of stinking air, crumbling buildings and horn honkers.

And in the South, where I've also lived, all people north of the Mason-Dixon line, regardless of east or west, are Yankees of dubious lineage, so they figure phooey on 'em all.

Meanwhile the Midwest is largely ignored by all factions and is secretly enjoying the highest quality of life at the lowest price. Perhaps they'd just as soon not be the feature of some heartland-ho travel article.

The Southwest, of course, has just been "discovered." Until a major woman's fashion magazine did a piece on Santa Fe this past year, it didn't exist. Give the coastal elites some time and they will have Boca-Ratoned and Palm-Springed Santa Fe within an inch of its juniper berries.

Except for Seattle, and Mount St. Helens, when it uncorked, the Northwest seems to be the most remote region of all. The fishing and wilderness activities in Idaho sound good, but the rumblings about survivalists lurking behind fir trees is pretty intimidating.

As for the Northeast, we all know about maple syrup, foliage and inns quaint enough to make you want to trade in your Buick for a horse-drawn carriage. The old-timers there are certain the rest of the country is made up of folks with dubious lineage, so they also figure phooey on 'em all.

I shared this synopsis of regional color with the London lady, and explained that regionalism makes it easier to travel abroad than intra-country. When we travel around our own country, we're always comparing environments, and forced to reexamine where we live and then justify why our area is best.

For instance, when New Yorkers gawk at the Black Canyon of the Gunnison (which they heard of only because they were skiing at Crested Butte), it makes those skyscrapers seem pretty inconsequential, not to mention the nerve-racking silence of it all.

And when almost anyone goes to New York, their own city looks like a cow town, and one can't help but be impressed by the inhabitants, who actually negotiate the streets of Manhattan on a daily basis. Never mind how they decide which subculture's cuisine to take home for dinner.

We come home from visiting another region and glow with satisfaction that we live in the best place after all, and we are incredulous that anyone could think differently.

When we visit abroad, there's none of that critical little regionalism to contend with. A woman from Fond du Lac, Wis., might go to San Francisco and say, "How do you suppose these people put up with living on terra infirma?" Put the same woman in Haifa, Israel, at night, with the lights twinkling and the shore within stone-skipping distance, and she can say, "This reminds me of San Francisco" and feel peaceful, connected to her part of the world. In that moment, the whole of her country belongs to her. Regional boundaries vanish.

After explaining my theory on American travelers, I looked at the lady from London expectantly. She arched an eyebrow at me like I'd been the one tossing down a double Scotch.

It's a darn good theory, so I held my eyes steady on hers and gave her a look that said: What could a Brit know about this? Phooey on her, anyway. Susan Shapiro lives and writes in Bethesda.