Four days after I arrived in Paris, I bought an umbrella. It had been raining on and off the entire time, and during my daily walks I'd been carrying a lightweight waterproof shell — bright green — which at the first sign of precipitation I'd unroll from its bundle and zip up, often removing it just minutes later, when the skies temporarily cleared. This was silly, I kept telling myself. There had to be a better way.

Still, I never set out specifically to buy the umbrella. It was only when, one Monday morning, I had decided to stroll the streets of St.-Germain-des-Pres, the tony Left Bank neighborhood, that the urge struck me. It happened, appropriately enough, in front of an umbrella store on the Boulevard St.-Germain.

This was no mere umbrella store. This was Alexandra Sojfer, and its windows were dazzling displays of parasols, frilly and bright and elaborate and not exactly my style — but umbrellas nonetheless. Inside, I asked about the wares, and the shopkeeper, a refreshingly friendly blond woman, who I later realized was Sojfer herself, explained that the company had been in the umbrella business since 1834 and that yes, they did carry more masculine, utilitarian rain gear. She showed me two models, a long one and a short one, both with fine carved-wood handles.

"But you know," I said, "I come from New York, where the wind is strong and the streets are littered with the skeletons of dead umbrellas."

Not to worry, she said. If any of the metal struts were damaged, I could simply return it to the shop to be fixed.

"OK," I said, hefting a short, gray one, "I'll take it."

Then she carried the umbrella behind the counter and asked me for 240 euros.

I handed her a credit card.

For the next 10 minutes, as I sipped an espresso she'd made me and filled out the French tax-rebate form, I tried to understand what had just happened. Had I really spent 240 euros (about $320 at $1.33 to the euro) on an umbrella, one that, albeit sturdy, was not significantly different from a 24-euro umbrella? With the VAT rebate, of course, the total would be reduced by 39 euros, and surely this coffee was worth at least 1 euro, so really I'd spent only 200 euros. Only.

One thing was for sure, I thought as I walked out of the shop into a suddenly sunny and rain-free morning: This was something I'd never done in Paris before — had never even imagined doing — and that was exactly why I was here, to see what new experiences could be wrung out of a city I've visited every two or three years since 1994.

In recent years, my activities increasingly centered on a relatively constrained area, the Right Bank neighborhoods stretching from the Marais, the old Jewish quarter turned fashionable outdoor mall, up to Montmartre, across the trendy, bourgeois-bohemian Canal St.-Martin and down to the immigrant quarter of Belleville and the riot of bars and cafes surrounding Bastille. At the same time, my group of Parisian friends had expanded and crystallized; I had a ready-to-go posse whenever I stepped out of the Metro.

But as I prepared for a weeklong visit in early September, I didn't want to just return to my favorite places and wallow in nostalgia. I wanted to see if it was possible to re-experience Paris as if for the first time, to be amazed by the reality of the place instead of comforted by its familiarity. Because seeking out the "new" in Paris is problematic in a city where change comes grudgingly, if at all, I set my sights on the yet-unfamiliar. How could there not be delightful restaurants, art galleries, little-known immigrant pockets and underground jazz clubs I'd never discovered?

This would certainly be a quixotic, self-contradictory mission, but it was a mission nonetheless, and on my first day, I almost completely failed. Arriving across the Seine from Notre-Dame cathedral — just about the geographic center of the city — I was surrounded by neighborhoods I already knew: the Marais, the Latin Quarter, Bastille. And as I walked (and walked and walked) to escape them, jet lag, fatigue and the gray skies' miserable drizzle conspired to drain my energy. Lunch on the quiet Ile St.-Louis was a find — Gillardeau oysters and free-range chicken at the low-key Auberge de la Reine Blanche — but it went by like a blip. And that evening it took me five tries to find an available, affordable hotel room. At sunset, as I took my first shower of the day, I wondered how I could keep this up.

But the next day I figured it out. My legs rested (if still restless), I marched north up to Montmartre, the hilltop 18th Arrondissement neighborhood famous for windmills, cabarets and the Sacre-Coeur basilica. The sun was out and the air was cool, and though I thought I knew Montmartre, I kept finding minor-key surprises, like the high, serene walls around the Cimetiere Montmartre and the plaques identifying the former homes of famous composers (here Berlioz, there Satie).

When I rounded a corner onto the Rue St.-Vincent, a peaceful lane that ran up past the Clos de Montmartre vineyard, I had a flash: This is the street from that Yves Montand song I love! (I'm no scholar of postwar chansons; I heard it on the "Rushmore" soundtrack.)

So when, a few minutes later, I spied a storefront called Studios Paris advertising short-term rentals, I made a decision. Wandering Paris was fun; carrying all my belongings with me, rain or shine, was less so. But an apartment would be more than a glorified storage locker or a spot for an afternoon nap — it would be a little corner of Paris to claim as my own.

One hour later, I was looking out from the sole window of the Eagle's Nest, my newly renovated seventh-floor garret, at what might be the best view of Paris in Paris. From Montreuil in the east to the Bois de Boulogne, it was unobstructed: the towers, the domes, the mansard rooftops, the slight sinuous suggestion of the Seine. For the next six days, I would look at this view every morning as I drank my coffee. I'd look at this view at sunset, after returning from my wanderings for a shower, a rest and a glass of wine. I'd watch it in the driving rain, and at midnight, when searchlights spun around the Eiffel Tower. The apartment itself might be only 150 square feet, with a private toilet out in the hall, but my living room was all of Paris.

And in my backyard, Montmartre, which I realized I didn't know well at all. I stood there taking it in: the angles of the buildings, the contrast of the darkening sky and the soft electric lights, the energy and anticipation swelling here and everywhere across Paris. It was all the more thrilling for the fact that I had been here, at this precise intersection, who knows how many times before, but had never quite seen it this way, so alive, so pulsing with potential. Tourists, I knew, lurked nearby, and Parisian scenesters were massing outside bars down the street, too, but the magic of a great neighborhood in this city is that it feels as though it exists for you alone.

Of course, I was not yet ready to be in an exclusive relationship with Montmartre, and since this was Paris, what's a little flirting between neighborhoods? Perhaps I could find the same happiness, or better, in a place like the 15th Arrondissement, a mostly residential area in southwest Paris that has, as far as I can tell, not a single tourist attraction — no monuments, no cultural institutions (unless you count the Cordon Bleu).

What it does have is real, normal life, which can be as appealing as the "Winged Victory" in the Louvre. For an afternoon I zigzagged among eminently pleasant squares and small parks, resting here to eat a ham sandwich (procured from a boulangerie that placed ninth in last year's best baguette competition), pausing there to observe the goings-on. Well-dressed friends posing for wedding pictures. Every once in a while, though, I got a brief glimpse behind this idyllic curtain. As I walked up near the Seine, I passed an old brick high school, glanced down the road to my left and stopped in my tracks. There, hidden until now at the end of the street, was a modernist skyscraper, the Tour Evasion 2000, rising awfully, dejectedly, above its surroundings. And yet it charmed me — so rundown, so out of place in what we think of as a grand, pristine belle epoque city. Beyond the tower, stuck between a busy road and the quais of the Seine, was a narrow strip of parkland, a group of homeless immigrants encamped at one end, a nearly naked woman sunbathing at the other.

From there I turned back east, where suddenly the landscape became oddly familiar. Right! Here, still in the 15th, was 47, rue Fondary, where 13 years ago my then-girlfriend, now-wife, Jean, had lived as a student, and down the street the Hotel Fondary, where we'd spent a night after locking ourselves out of her apartment. Almost everywhere I looked in Paris I found this tug between the past and present engulfing me. Any angst I had about the success or failure of my mission was fast evaporating as I was enjoying myself too much to care, and coming to realize that whatever I was doing, I was still participating in distinctly Parisian endeavors. Reminiscing at meaningful corners, indulging in highbrow culture available nowhere else, eating more duck than one should eat — this is why we come to Paris in the first place. This is why I'd come to Paris, and why I'd kept coming back.

That said, one day's excursion, to the busy but overlooked 13th Arrondissement, got me more excited than every other, because it was entirely new. Following a vague tip from a Drew Barrymore look-alike I met in a bar, I took the Metro to the Bibliotheque Nationale Francaise and hunted for Les Frigos, an artists' collective. To the west, the neighborhood was older, full of businesses like Le Cristal, a grotty, busy brasserie where a creaky-voiced waitress served me roast lamb in a flood of flageolets. But it also included a whole Little Saigon that I hadn't known about — street after street of Vietnamese noodle shops and vendors of cheap souvenirs. There was even some quirky history, like the Square Henri-Rousselle, where the first hot-air-balloon flight landed in 1783.

And right nearby, La Butte aux Cailles. How had I missed this neighborhood all these years? With its narrow lanes, clever street art and relaxed cafe-bars, it felt like a village in the middle of Paris — like the Marais minus the boutiques or Montmartre pre-"Amelie." I walked up and down the streets, then into the offices of Les Amis de la Commune de Paris, a group dedicated to preserving the memory of the few months in 1871 when a workers' movement took control of the capital.

"It's not taught in schools," lamented Francoise Bazire, Les Amis' secretary general. That bit of the past was fading.

As was I. It was early evening, and I needed a shower and a nap. Back to Montmartre I went. When I emerged from the Metro at Les Abbesses, I popped into Au Levain d'Antan, a boulangerie that got the top place in this year's best baguette competition, and bought a demi-baguette, still warm from the oven. Then I raced down the street and up seven flights of stairs to my garret, where I sliced open the bread, slathered it with good Echire butter, cracked open a bottle of ice-cold Sancerre and consumed my snack while watching the setting sun cast shadows across the City of Light. Forget the past, the present, the future, my expectations and my memories — this was living, no matter where or when I was.

When at last the morning came to check out of the Eagle's Nest, I took one more look at the sunlit view and could see almost nowhere I hadn't set foot. No doubt secrets remained, but they would be revealed in time.

It was 11:30. The rental agency's rep would be downstairs, waiting for me to let her in. I patted my back pocket, heard the reassuring clink of my keys and walked into the hall, closing the door behind me. Then I froze. That clink was not keys but coins. I was locked out, just as my wife and I had been 13 years before.

This was only a minor emergency. The apartment's owner would be located in a few hours, the keys reproduced, my belongings recovered. But until then, there was nothing to do but walk out — as I'd done a hundred times before, as I hope to do a thousand times more — into the streets of Paris, with no clear idea of where I was going, or what I would do when I got there.