Certainly Baker takes more chances. His much-praised first novel “The Mezzanine” (1988) was a microscopically digressive account of buying shoelaces; “Room Temperature” (1990) was about feeding a baby. “I have an almost self-destructive desire to be original,” he says; with “U and I” he’s gotten away with it again. This booklength essay pitilessly records its author’s twinges of envy and mines his own inner life to examine the psychological minutiae of reading, writing and remembering.

In “U and I” Baker presents himself as the ultimate literary outsider: a “direct, enthusiastic, slightly crazed” fellow ,‘springing out" at Updike at parties and book signings. This isn’t just a comic device. Baker, 34, lives in a small upstate New York town with his wife and daughter. He’s bearded, bespectacled and too tall for his tiny car with its ankle-deep litter; he resembles the urbane Updike only in being afflicted with psoriasis. Though far from the literary scene, he confesses to “wild” fits of “self-promotion.” Once an aspiring composer, he claims, without apparent irony, to have found his true vocation after “looking at The New York Times Book Review and seeing those big ads screaming away.”

Baker is smart enough to turn his shame to advantage. One of the funniest bits in “U and I” has Baker running into Tim O’Brien (“Going After Cacciato, National Book Award, 1979,” as Baker sums him up) who mentions that he golfs with Updike. “I hadn’t written a book … of any kind,” writes Baker, “and didn’t know how to golf-. still, I felt strongly that Updike should have asked me and not Tim O’Brien.”

Yet despite his fixation, Baker had read less than half of Updike’s work, and didn’t bone up for “U and I” lest it “irreparably harm the topography of my understanding of him.” This sounds like twaddle, until we reflect that our everyday understanding of the most influential writers is similarly sketchy; the Shakespeare who lives in our recollection created only a dozen or so characters and a few hundred words, probably garbled. Baker keeps quoting his favorite Updike passages, then correcting them in brackets after consulting the text: the misremembered Updike is his true literary influence. Fellow writers will find “U and I” chastening: even readers obsessed with you won’t read all your stuff and won’t remember it right. They should also be chastened by Baker’s almost Martian intelligence and their spouses, unlike Baker’s, may be at a loss for plausible consolation.