Twenty years ago, John Updike published a memoir, “Self-­Consciousness,” which opens with an extended reminiscence of his hometown. The author has been stranded for the evening while his mother and daughter are at the movies, and he walks the streets of Shillington, Pa., in a light rain, reliving the past in the incantatory detail with which he informed and illuminated his fiction, summoning up the names of departed local merchants, of his teachers and elementary school classmates, recalling the material texture of his childhood right on down to the candies, magazines and coloring books offered for sale at the variety store, recording the essence of his time amongst us. “The street,” he writes, “the house where I had lived, seemed blunt, modest in scale, simple; this deceptive simplicity composed their precious, mystical secret, the conviction of whose existence I had parlayed into a career, a message to sustain a writer book after book.” That message, that testimony of an individual and recollective consciousness as it relives and reviews the matter of a lifetime and grapples with the effects of aging, disease, decline and death, is the focus of Updike’s final collection of new fiction.

Of these 18 stories, all but one (an odd travelogue called “Morocco,” dating from 1979) were published in the last decade, and their themes and situations hark back to the author’s earliest autobiographical fiction, especially the stories set in Olinger, Updike’s fictionalized version of Shillington. The difference here is that the protagonists in this collection are, for the most part, at the end of their lives, and so the news of familial drama and divorce and the cocktail parties, barbecues and casual wooings of quotidian life in suburbia is given retrospectively, wistfully, presented in the larger context as memories of lost moments and lost opportunities. Updike once described himself as “a literary spy within average, public-school, supermarket America.” So he was. And these are his last smuggled dispatches, made all the more poignant for their finality.

Two of the stories here feature a familiar Updike alter ego, David Kern, the boy who teetered on the brink of losing his faith all those years ago in “Pigeon Feathers,” now grown old and hesitant. Both are set in motion by Kern’s return to Olinger, first for a high school class reunion and then for a nearby conference. In the more successful of the two, “The Walk With Elizanne,” Kern and his second wife go first to the local hospital to visit a classmate who is unable to attend the reunion because of her infirmity. Mamie is bedridden, emaciated, old, dwelling, as she says, in the “last chapter” of her life, and yet Kern remembers her as she was in kindergarten, remembers her mother, remembers the class plays where she was always “the impish little sister.” What sustains her — and him — is her religious faith, a theme that runs through many of the stories in this collection. Kern contrasts that faith with the “unresisted atheism” that “left people to suffer with the mute, recessive stoicism of animals.”

At the reunion itself, he encounters Elizanne, whom he also knew as a child but who even then represented something of the exotic, her name pronounced “Ay-lizanne,” and now, though “plump women of 67 or -8 have a family resemblance,” she electrifies him by telling him how much he’d meant to her all these years because he was the first boy to walk her home and kiss her. This occasions a flood of recollected sensory detail, Updike at his best, an eternalizing of the moment of that kiss which stands in defiance of age and decrepitude and the bone cancer winnowing Mamie in the prison of her reduced self. In the final scene, the story takes a bold leap into the past, illuminating the walk and the kiss, Elizanne pattering on in her soft breathless adolescent voice and already arrived on her parents’ doorstep with so much more to tell. And David, the stutterer of the Olinger stories, enchanted, intoxicated, assuring her, “We have t-tons of time.”