There are certain sayings so ingrained in the public mind that they don’t need to be finished to be complete. When you hear “live fast,” your brain quickly fills in the rest: “die young.” The saying seems to have originated in a 1947 novel by Willard Motley called “Knock on Any Door” — later a film starring Humphrey Bogart — in which a character quips: “Live fast, die young, and have a good-looking corpse.” With unimprovable prescience, James Dean reportedly enjoyed saying it. Lou Reed and Rick Ross are among the musicians who have made dubious use of the line. Live Fast Die Young is also the baffling name of Germany’s “biggest streetwear brand,” if they do say so themselves: Best of luck to whatever citizens are donning those duds. I hope they don’t own motorcycles.

“Live Fast,” by Brigitte Giraud, translated from French by Cory Stockwell. Ecco. 159 pages. $28

Brigitte Giraud’s deeply autobiographical novel, “Live Fast,” meticulously investigates the circumstances that led to her 41-year-old husband, Claude, being killed on a motorcycle in 1999 in their French town of Lyon. All motorcycles are not created equal; the bike Claude was riding that afternoon was of a breed that appears to have been built with a funeral in mind. This wasn’t the eased-back “hog” favored by big beards and bigger bellies. The Honda CBR900 Fireblade was a beast originally designed for professional racers, not for civilians on public roads. Emergency room doctors have a name for this species of bike: donorcycles.

The novel, which won France’s prestigious Goncourt Prize in 2022, has now been translated into English by Cory Stockwell. Almost all the chapters begin with an “if only,” as Giraud autopsies the decisions she and her husband made in the months, days, hours and even seconds leading up to Claude’s fatal crash. In her imagining of alternate scenarios that would have resulted in Claude’s not being on the Fireblade that afternoon — “if only I hadn’t wanted to sell the apartment,” “if only I hadn’t done my brother a favor,” etc. — Giraud flawlessly depicts the depths of guilt-rich obsession to which the grieving soul sinks, the battered heart and wearied mind fastening to minutiae in an attempt to make sense of the ruin that ensues from the random. “This litany of ifs,” she writes, “has made me live my life in the past conditional.”

When Claude was killed, leaving Giraud alone to raise their small son, the tremendous rupture at the hub of her sent up waves of uncontainable sorrow. She labors to make sense of this rupture, but there’s no making sense of it, no box it can fit into. “You can look for every possible coincidence, every imaginable sign, in the interconnections between events, occurrences, dates,” but ultimately “there’s nothing to understand, nothing to see — it’s like trying to wring out a dry cloth.” In other words: Death doesn’t stop to explain itself, to satisfy our impotent hunger for comprehension and connected dots.

“There’s no chronological or methodological order to any series of events,” Giraud writes; she admits she is “just putting forth hypotheses to alleviate the feeling of emptiness that takes hold of me whenever I try to imagine that final day.” Time the great healer? Not always. Often, it’s the great scrambler: “I’m mixing things up as time goes by.” To anyone who lives with the hourly affliction of having had a young beloved erased in an instant, the precision of memories becomes sacrosanct. To mix them up is to somehow lose the beloved anew.

Giraud does not detail some of the specifics of how Claude was killed that afternoon. It’s clear that he accelerated from a red light with too much torque and was thrown from the bike, but that alone would not have been fatal unless he was helmetless, and he wasn’t. Her suggestion is that he landed in the oncoming lane and was hit by a passing motorist. Perhaps those specifics are still, after 25 years, too unstringing for her to get down on the page. But then why this epigraph by the contemporary French writer Patrick Autréaux: “Writing means being led to the one place you’d like to avoid”? The blameless young man driving the car that may have hit Claude revealed to Giraud the final words her husband spoke, but she doesn’t reveal them to us, perhaps because they are too stingingly private. But then why mention it at all?

Stockwell too often resorts to cardboard jargon in his rendering of Giraud’s French; in one especially impressive feat, he fits three clichés into a single sentence: “crooked grin,” “half angel and half devil,” “drop of a hat.” But he’s capable of better, even memorable, lines, including the two saddest sentences in the story: “He was still our son, but I’d have to learn to say my son. Just as I’d have to give up the we that had supported me and learn to say I.”

It’s something of a mystery how “Live Fast” has managed to be published as a novel. Nothing in its tenor or tempo, in the style’s manifestation of its subject, in the plinths and joists of its armature, in its overall narrative temperature and weight, suggests novel – it all overwhelmingly suggests memoir. Giraud’s American publisher has labeled it “a sensitive elegy to [Giraud’s] husband.” As a memoir it would slide honorably between C.S. Lewis’s “A Grief Observed” and Joan Didion’s “The Year of Magical Thinking,” but as a novel it’s much too anemic, fragmented, unfinished: It lacks the structural complexity and depth of James Agee’s “A Death in the Family,” for some of us the greatest American novel of mourning.

No matter its tag, “Live Fast” is a small, crushing masterpiece of grief. Giraud does what the best autobiographical writers have always done: Through the vista of her personal calamity, she incites you to apprehend your own world with a bursting freshness you didn’t know you needed.

William Giraldi is the author of three novels, the memoir “The Hero’s Body” and a collection of literary criticism, “American Audacity.”