There I was, in Paris’s Charles de Gaulle Airport, a place in which I spend far, far too much time. For once, I was early. It was one of France’s occasional “everyone goes on strike” days. Part of the fun of these kinds of days is that you’re never exactly sure to what degree the call for a nationwide strike will be heeded. You might come to the conclusion that the issue in question is trivial and no one will actually strike, only to find that absolutely every scrap of infrastructure is paralyzed. On the other hand, having been so deceived the last time, you might take myriad precautions only to discover that everything is working almost normally. It’s these uncertainties that make life in France so exciting.

I had decided to leave for the airport a couple of hours earlier than I would normally have left, to allow for strike traffic. (Once, during a particularly difficult strike that happened to occur during a snowstorm, it took me over five hours to cover what was normally a 40-minute drive.) This time, though, the strike traffic was far lighter than I had expected, so I found myself just hanging around in Terminal 2F.

Terminal 2F is a great big soaring concrete cathedral to the god of airplanes. It’s a pretty impressive place, assuming you really, really like concrete. Its younger sister, Terminal 2E, was designed to be an even greater concrete cathedral, but a chunk of it collapsed upon itself (and a couple of travelers) two years ago and it doesn’t quite generate the same aesthetic effect anymore.

Anyway, having nothing to do while waiting for my plane, I just started wandering around observing things. My attention was drawn to a young couple who were wound around each other in a passionate embrace, and this got me thinking about airport kisses.

When you travel a lot you end up witnessing many airport kisses. These are not the same as street kisses or bedroom kisses or hospital kisses. They’re not even the same as train-station kisses (I think it’s because of the lines and the security in airports, or something). Airport kisses are a class unto themselves.

The couple that first grabbed my attention consisted of a slight young man and a young, rather plain woman with a mole on her cheek. Their kiss was of the lingering kind, a kiss that stops from time to time so you can look into each other’s eyes. It was a kiss that said they would be apart for a while. He said something to her, her lips formed “OK,” and they kissed again, he holding her face in his hands.

This is a typical kind of airport kiss, and I suddenly realized that this would make a good topic for a dispatch, so I decided to spend the rest of the time before my departure checking out kisses on that Tuesday morning in Terminal 2F. Besides, to be frank, I had nothing else to do.

The next one I found was an entirely different type of airport kiss—it was a woman kissing a toddler who was sucking on a bottle. They were obviously traveling together, probably waiting between flights. The toddler bore the signs of fatigue that could only be produced by that awful period between connections, but he was bearing them like a real little trooper, and his mother seemed proud.

Which raises the point that there are really three broad categories of airport kisses: arrival kisses, departure kisses, and co-traveler kisses.

Departure kisses are the ones you probably immediately started imagining when I first raised the whole point about airport kisses (not to mention that it was a departure kiss that got me going on the topic in the first place). Those are the passionate ones, those are the lingering ones. People don’t want departure kisses to stop, because after they do, one of them departs. This applies whether they are amorous departure kisses, like the one shared by the young couple I saw, or parental departure kisses, like the ones I’ve planted on my own children from time to time, the kind where you squeeze your child and smoosh your lips against his cheek until he starts getting embarrassed and tries to wiggle away.

Departure kisses are usually followed by the nondeparture half of the kiss standing around looking like a fool after hearing those terrible words: “I’m sorry, you’re not allowed past this point.” The departing half of the kiss then gets in some line while the nondeparting half stands and waits until the departer is definitively out of sight, which these days, with all those slow security lines, might take a hell of a long time. Recently, I was at another terminal at the same airport standing in a security line with a man who kept waving back to the nondeparting half of his departure kiss while taking off his shoes, his belt, his jacket … etc. Off came an article of clothing, up went a wave. Far behind us, a short woman in a red jacket was waving back from behind a metal barrier. Even after he had gone through and was out of sight, she stood looking at the metal detector.

But departure kisses aren’t the only kind, and they’re certainly not the best kind, so I went downstairs to the arrival hall to observe arrival kisses. Arrival kisses are always shorter than departure kisses, because there’s so much to say and so much more time to say it. Arrival kisses tend to be more forceful, less tender, and, surprisingly, often more tearful. This is a thing I’ve noticed. While it has never bothered me that no one comes with me to say goodbye when I leave from an airport, I confess a twang of regret that no one is ever waiting to pick me up, because arrival kisses can be so very nice. Alas, if anybody is waiting for me, it tends to be a taxi driver. None of them has ever kissed me, let alone jumped into my arms, as sometimes occurs with arrival kisses.

Arrival kisses cause more of a traffic jam than departure kisses, because they often immobilize someone who’s pushing a great big cart full of luggage, thereby blocking the passage of everyone behind. Some airports are particularly prone to this kind of thing—it’s a function both of airport layout and local culture. For instance, you can take hours to get out of the airport in Chennai, where entire extended families come to throw themselves into the arms of just about everyone getting off the plane and the entire airport becomes clogged with arrival kisses.

The last kind of airport kiss is the co-traveler kiss. These are actually the best. I mean, you write poems and songs about departure kisses, and arrival kisses give you that wild adrenaline burst, but co-traveler kisses are still the best in the long run. These occur between two people who have set off on a journey together. Either they’re kissing because they’re happy to be leaving together, happy to be arriving together, or happy to be on their way, but there’s always a shared complicity and a shared excitement in co-traveler kisses that you just don’t find in other kinds of kisses. You’re kissing in a setting that’s different, you’re kissing in the midst of a journey, and a journey shared with someone you want to kiss is usually a journey worth taking.