I had been in Paris barely 10 minutes today when I had my pocket picked.

Arrived from the south of the country on the fast train into Gare de Lyon, made my way downstairs to the Metro’s 1 line, got into a jammed car just as the doors were about to close … and then made an unintentional contribution to the city’s criminal underclass.

I have been through this once before, in a situation quite a bit like this one. Which is one reason I am angrier with myself than the last time … but not as angry as I am at the sleazeballs who perpetrated the theft.

It annoys me to write about it, but maybe others can learn from my carelessness.

Let’s start with some basic rules for avoiding incidents like this, particularly on subway trains and the like, in a big city, in a place known for pickpockets.

1. When arriving in a train station, with luggage and a backpack, just pay for a cab. Pushing around luggage absolutely becomes a distraction, and you do not want to take that distraction into the underground system where you might save 20-30 euros.

2. Never be the last person into a crowded car. It is proximity, the crush of people, that is, again, distracting and makes you an obvious target. If I had stopped and waited for the next train, I probably would still have my California driver’s license, etc.

3. When something odd happens inside the car, hang on to your wallet — or purse. Because that weirdness often is meant to make you drop your guard while gawking at a noisy sideshow.

4. Do not carry a wallet in your pockets. Well, duh.

So, here we go.

We were rushing to make a train — as if our lives would be changed favorably by waiting for the next car, which seemingly is what about 98 percent of all train riders think. It was a crowd of people, and the 1 line often has crowded cars, anyway. We could have waited for the next train and been one of the first people on, rather than the last. Actually, we could have headed for the next car on that first train, which was not nearly as crowded, and probably have been OK. But we thought we might miss the train (and maybe five minutes) if we walked the extra 20 yards.

As I got in the car, two things happened: 1) A local man, apparently, dark hair, maybe 35, made a “you go ahead” motion toward me, which for a fraction of a second I thought was strange, because no one sacrifices an ounce of comfort for anyone else on a Paris Metro train. Then, 2) a woman tried to get in behind me as the doors were closing and was halfway in when the doors (I thought) pinched her. She let out a shout.

Of course, doors in the Paris Metro don’t actually close with someone halfway in; as I reconstruct events, the woman had made a point of getting halfway out of the car as the doors nearly closed, but then the doors stopped and retreated. And I turned to look at her — woman, also mid-30s, dark hair, slender, shirt and pants — and I remember thinking, “She doesn’t seem hurt, given that she was shouting a second ago.”

By then, it likely was all over.

I remember that a few moments later, the man who had given the “go ahead” signal to me was behind me and to my left, and he stuck one arm forward to grab the middle floor-to-ceiling bar in the car, presumably to keep his balance, but possibly to distract me from what his other hand was doing.

I had made one concession to pickpockets — since that incident in Barcelona (the world capital of pickpockets), where I was wearing multi-pocket cargo pants, I have taken to placing my wallet in my front-left pocket (which I normally can see), rather than in my left-rear pocket — where I carry it in more civilized places.

That didn’t daunt the pickpocket because my jeans were baggy, and gaped a bit at the pocket, and in the crush of that car he was able to fish out my wallet from my front-left pocket without me feeling a thing — and without me seeing anything, given that I was jammed in there with a dozen people, a backpack and a piece of luggage.

We had made one stop when I touched my pocket and realized it was emptier than it had been when I got on the train. Which is a sickening feeling.

And I knew immediately who stole my wallet and how it had been done. The two people, the thirtysomething man and woman, had picked me out — old guy, clearly a tourist, pushing a bag, carrying a backpack, rushing, with a bulge in my front-left pocket — and had executed the “fake squished in the doors” shout followed by the “remove the wallet” move while attention (including mine) was focused elsewhere.

So, going forward?

I vow to recognize when I am particularly vulnerable to pickpockets — in crowds, first dealing with luggage — and modify my behavior.

By refusing to get involved in crushes of people.

By burying my wallet or other key documents in a fanny pack or at the bottom of a heavy backpack, where they cannot be seen, only guessed at.

By accepting that I might not make every train I see.

By taking a cab, which often also is a ripoff but cheaper than losing your wallet and far less trouble than calling a couple of credit-card companies to cancel stolen credit cards.

And maybe one more thing … buying a new, cheap wallet, placing it prominently in a rear pants pocket and filling it with exactly one thing — a scrap of paper that says: “Ha-ha-ha.”

Regular pickpockets, who do it for a living, may yet breach my latest plans … but it should not be as easy for them as it was this time.

And it didn’t help that a recording inside the train not five minutes after I had lost my wallet … warned us in about six languages to be alert to pickpockets known to be active on the No. 1 Metro line.