I started reading Patrick Modiano soon after I turned forty, and immediately I was obsessed. True, he’d just won the Nobel Prize, after which a flood of reviews and articles appeared, most comparing him to W. G. Sebald. But while that certainly caught my attention, it wasn’t enough to hook me. Nor was my interest stirred to passion just because I loved the feel of those Yale Margellos paperbacks, with their appropriately French flaps (though I did, and still do—oh, how I do).

So what exactly captivated me? Most novels are too long and plodding for this short story writer, but I loved the brevity of a Modiano book, the swift spareness of its prose, its urgency. As soon as I closed one, I wanted to pick up another. I went quickly from Paris Nocturne to Little Jewel to After the Circus to Young Once. Modiano has said all of his books are in essence the same one, or variations from slightly modified angles. That’s not to say the books felt incomplete. Each was entirely satisfying on its own but left me hungry all the same. When I came to the last page, I’d sometimes go back to the first and start reading again.

I’m also a sucker for hard-boiled mysteries, will re-read The Maltese Falcon or The Big Sleep every few years, accepting or ignoring their misogyny for the sake of an evocative atmosphere. But when the detectives solve their crimes I’m always disappointed. Why waste all that mood for the straightforward surprise of pinning a murder on a particular suspect? Modiano is as noir as Hammett or Chandler, but his mysteries remain as mysterious at the end as they are at the start. Any answers only open further, deeper questions.

Take Paris Nocturne, for example. The book opens with a car accident. After striking the narrator, the car veers into a hotel arcade, glass rains down, and out from behind the wheel stumbles a young woman. A man who “happened to be at the entrance of the hotel” helps them into an ambulance but does so in a manner that seems more menacing than benevolent. They ride to the hospital, and when the narrator wakes from a dose of ether, the woman is gone. For the rest of the book, he tries to find her and figure out what happened that night, how the accident might be connected to other events and people in his life, but he only comes up with more mysteries. What was he doing on that particular street? Who was the girl, and why did she run away from the hospital? Why does he suspect that the man who helped them might have had something to do with his father? He can only guess.

Every detail in Modiano is precise and sensory, but the overall picture is hazy. There are shady fathers in many of the books, with possible criminal connections, and mothers who work as dancers, actors, singers, showgirls, strippers, prostitutes, always fading in and out of view, never figures of stability. The mother of the narrator of Suspended Sentences leaves her children with dodgy friends while she’s touring with a theatre company. The narrator of Little Jewel spots her mother on a metro train after not seeing her for a dozen years. She follows her across Paris, walks up to the door of her apartment, but doesn’t knock. The narrator of After the Circus, also abandoned by his mother, takes up with a new, mysterious woman on the run. He meets and falls for the lovely Gisèle after being interrogated by the police for suspicions that are never made clear to him. She asks for his help moving out of her apartment, and when it’s obvious she has nowhere else to go, he takes her into his bed. She then involves him in sketchy deals with seeming criminals and ends up dead in a car accident that may or may not be accidental.

It’s the “seeming” that matters most here. In Modiano, nothing is certain. The heart of his novels is the mystery of post-war Paris—the lingering corruption of the Occupation, and its effects on those who’ve survived it. How did they come through the war? In what ways were they compromised? And what impact will their choices have on the children born in its wake? The secrets of resistance, collaboration, and opportunism are buried under too much rubble to be fully unearthed. Modiano takes us into the dimness of alleyways and tunnels and smoky cafés and leaves us there to squint and wonder.

But the most mysterious thing in his books is memory. This is why Sebald comparisons appear so frequently, though Sebald’s use of memory is more associative, like Proust’s, and also, I’d argue, more reliable. Memory in Modiano is slippery, unstable. His narrators are often looking back on things that happened years ago, and what they see is partial at best, splintered and blurred. One of the phrases they often use is, “I’m trying to remember.” Piecing together what happened takes effort, and the attempt often fails. Sometimes trauma prevents recall; sometimes too many intervening events crowd the view. The narrator of Paris Nocturne never remembers why he was on that street, but he eventually recalls an accident from childhood that makes the later one echo with added strangeness. The narrator of Little Jewel can’t quite bring back the circumstances that caused her mother to send her off to live with strangers in the country, but she does remember the details of a painting that hung in her bedroom there. Some of the gaps Modiano’s characters fill in with their imagination, picturing what they can’t know for sure. Often the best they can do is to speculate, offer possibilities, and acknowledge that no matter how much they struggle to solve them, the mysteries of their lives, their identities, will go on and on, without end.

This may be as close as I can come to solving the mystery of why I, a forty-something writer from New Jersey who has lived in Oregon for the past twenty years, is so taken with Modiano’s work: his rendering of memory resonated strongly as I entered my fifth decade, and continues to do so now that I’m halfway through it. My family is stable. My parents live dully upstanding lives. I’m not searching for clues to crimes committed before I was born. But more and more often, I find myself wondering if there’s something I’ve forgotten to do, a phone call or email I’ve forgotten to respond to, an appointment I’ve forgotten to schedule, or a meeting I neglected to attend. It’s a nagging feeling, urgent but peripheral, and rarely turns out to be accurate. There are other things so oddly fixed in my mind I know I’ll never forget them—the afternoon I pulled Suspended Sentences from a shelf in The Strand, for example, when I had a summer cold and my wife and daughter were shopping for scarves in Chinatown, the dull pressure on my stuffed sinuses as I read its first mesmerizing words: “I met Francis Jansen when I was nineteen, in the spring of 1964, and today I want to relate the little I know about him.”

Rather than the early onset of senility—or so I hope—what I think I’m experiencing is how memory changes with age. I’ve now lived enough years that events and details and sensations have begun to cram together and tangle. There are too many moments vying for attention for me to see them all distinctly. Some will remain half-hidden—glimpsed, at most, as fragments—while others suddenly push to the front and offer a brief, startlingly clear view.

The mystery of memory, what it lets slip away, what it dredges up, is the same for someone born in Paris soon after the Liberation as for someone born in 1970s suburban New Jersey. Like the narrator of Paris Nocturne, I’m constantly struggling with questions my memories pose but can’t answer. Where was that lake I swam in one summer afternoon, when a huge snapping turtle surfaced a few inches from my foot? Who was the girl with me? Why am I left with the sense that I treated her badly, when all I can picture are flashes of her face—dark bangs over dense eyebrows, a scattering of freckles over a sharp nose—and when I can’t even call up her name?