AT a dinner party not long ago, one 40-something man held everyone's attention as he entertainingly sketched out plans for his next vacation, a trip to Antarctica. Brimming with enthusiasm, even beaming, he talked about buying cold-weather gear, anticipating the novel landscapes and watching penguins.
When he stopped for breath, I couldn't resist making an observation: ''I'll bet you know exactly how many countries you've been to.''
Sure enough, without hesitation, he cited a number in the 40's.
''And states?'' I replied.
Market researchers are forever dividing travelers into categories -- adventurers, beachcombers, family visitors -- but I have found that the deepest split is between those who return again and again to familiar places and those who repeatedly venture out to new ones.
And, it seems, those who keep visiting new places -- like my dinner party companion and like me -- usually share another trait. We keep score. We keep a list. Having the wanderlust often goes hand in hand with knowing how many countries, how many states have been visited.
Perhaps we are simply competitive by nature, even in travel.
But I have also found that we compete mostly with ourselves. Sometimes we do tell others how many places we have been, of course. After my return from a week off last year, for example, many friends and acquaintances asked me where I had been. And when I told them ''Finland and Estonia,'' the most common response was, ''Why'd you go there?'' A bit defensively, I would say some variation of ''Well, I want to go everywhere, and they are the 38th and 39th countries I've been to.'' It was hardly bragging.
Why do some people become vagabonds while others do not? The example of others -- parents, partners, mentors, friends -- perhaps. Natural curiosity, certainly. Fiscal wherewithal, yes, that too.
But I can also vividly recall two incidents that may have had something to do with it for me. One was a goad. I was in my early 20's, recounting the glories of some American place I had just visited -- I no longer remember which. But it must have been somewhere elegant, because a friend replied with a question: ''Have you seen Versailles?'' And when I said no, his retort was one I have never forgotten: ''You haven't seen anything until you have been to Versailles.''
The gauntlet had been laid down. I felt humiliated. I went to Versailles on my next trip abroad, the following year. I sent my friend a postcard of the king's gilded bed chamber. (We are still in contact -- at Christmastime he sends a card with an all-purpose form letter, often telling where his travels have taken him that year. I am certain I have now been to more countries than he has.)
The other incident was far more poignant. On my second trip to Europe, in 1977, I went to Rome. After walking the city for a few days, trying to see everything and absorb the atmosphere, I decided one Sunday to go to Tivoli, some 20 miles east, to see the ruins of Hadrian's villa, circa A.D. 120, and the Villa d'Este, a famous country villa built in the 1500's by Cardinal Ippolito d'Este, a son of Lucrezia Borgia.
The grounds of Hadrian's villa cover hundreds of acres, with monuments replicating things that Hadrian had seen on his military ventures around the Mediterranean, framed by gardens and a reflecting pool.
As for the Villa d'Este, guidebooks called it one of the most prominent residences in Europe, a place that the likes of Liszt, Montaigne and Fragonard had visited. It, too, owed some of its fame to its formal -- and formidable -- gardens (with outdoor sculpture and fish ponds) and, even more, to its plentiful fountains. One walkway is called the avenue of 100 fountains.
I took an afternoon tour bus that visited both. A guide briefed passengers on the way out, then stayed behind when we arrived, letting us explore on our own.
And that is when I had an epiphany. As everyone streamed out for a few hours in the gardens, two little elderly women stayed behind.
They appeared to be on their first trip to Europe, or at least their first to Italy. They had come all the way from Australia, but they could only view the sights from the bus. They waved off companions who tried to coax them out, even if only for a short time. They could not manage an afternoon on foot.
I RECALL one woman in particular. In my memory, she had white crinkly hair and wore a pink flowered dress, though I wouldn't swear to it. She had a cane, for sure. She sat by the window, happy for glimpses of the view outside.
Then and there, I decided that I would see the world before I had to stay behind in a bus. Like my father, I had always saved newspaper and magazine clips about places that intrigued me. Now I was intent on going, the sooner the better -- with family, with friends, alone if need be.
I did not keep score at first. I just savored the sights, the experiences, the moments. At some point, I found a blank map of the United States, copied it and colored those I had visited green. A list was born.
The country list started on a long, fidgety plane ride. Unable to read, I started to jot down the countries I had seen.
Recently I have taken to using lists in a different way. I am not a five-countries-in-six-days traveler. And so I use not just my clips and books as guides but other lists too.
The World Monuments Fund, for example, has published a beautiful coffee-table book, ''Vanishing Histories: 100 Endangered Sites From the World Monuments Watch,'' that is a marvelous guide. In planning a trip, I turn to it to see if I'll be near any of its treasured sites. So it was that in early 2002, in Cuba, I detoured to the 17th-century Convent of Santa Clara of Assisi and to the unfinished national arts schools that Fidel Castro and Che Guevara decided to build on the site of a golf course.
Another resource I consult is Thomas Hoving's ''Greatest Works of Art of Western Civilization,'' 111 of his favorite works. His eye has directed me to Montezuma's headdress in the Folk Art Museum in Vienna and to a golden saltcellar by Cellini (created for Francis I of France) of Neptune admiring a nude Earth in the Kunsthistorisches Museum there. His eye renewed my desire to get to Krakow to see Leonardo's ''Lady With an Ermine'' and the huge Gothic altars by Wit Stwosz in St. Mary's basilica.
I have a book of the world's greatest buildings, too, and another of Britain's stately homes.
Sometimes, especially on long plane rides or in sidewalk cafes, I find myself measuring my see-the-world aspirations against lists that have nothing to do with tourism. Newspaper weather pages, for example. As I read The International Herald Tribune or Financial Times, I will pull out a pen and tick off the cities on their weather lists I have visited.
I have until now kept this harmless practice to myself. The lists never determined where I would travel.
I knew my little habit had gone too far, though, on a recent trip. After viewing Vienna's new Museum Quarter, I stopped for lunch and pulled out my Trib. Having finished the front page, I turned to the second page. My eyes slipped to the bottom. There, across all six columns, was a list of the places where the newspaper was printed: Athens, Frankfurt, Hong Kong and so on.
Before even thinking, I had drawn out my pen, scanned the list and started making check marks.