n 1884, Ulysses S. Grant, desperate for money and terminally ill with cancer, did what countless statesmen and military leaders had done before him: he sat down to write his memoirs. Racing against the clock, he turned out two substantial volumes on his early life and his military experiences in the Mexican and Civil Wars.

By any measure, he had a lot to write about and a lot to tell. He produced a classic memoir, as the genre was then understood: important events related by a great man who shaped them.

But that was then.

Today, Grant's memoirs fall into the same sprawling category as "Callgirl: Confessions of an Ivy League Lady of Pleasure," "Bat Boy: My True Life Adventures Coming of Age With the New York Yankees" and "Rolling Away: My Agony With Ecstasy," to pluck just three titles from the memoir mountain looming in the next month or two.

Actually, it's more a plain than a mountain, a level playing field crowded with absolutely equal voices, each asserting its democratic claim on the reader's attention. Everyone has a life, and therefore a story that should be told and, if possible, published.

The memoir has been on the march for more than a decade now. Readers have long since gotten used to the idea that you do not have to be a statesman or a military commander - or, like Saint-Simon or Chateaubriand, a witness to great events - to commit your life to print. But the genre has become so inclusive that it's almost impossible to imagine which life experiences do not qualify as memoir material.

Canvassing the publishers' catalogs, I was intrigued to see "All in My Head," by Paula Kamen. It's about a headache the author has been carrying around for more than a decade. It will do battle on the bookstore shelves with, among many others, "Fat Girl," by Judith Moore, a memoir of growing up fat and female, which in turn will compete with another fat-girl memoir, "I'm Not the New Me," by Wendy McClure, which will square off against "Faith in Carlos Gomez: A Memoir of Salsa, Sex, and Salvation," by Samantha Dunn, who found a new way of life, and a book topic, when she signed up for dance lessons. Then there's "House," by Michael Ruhlman. It's about a house. Is there not something to be said for the unexamined life?

In self-defense, I have tried to construct a memoir taxonomy, just to impose some sort of order on this sprawling genre. Important categories include the retired-statesman (or more likely, bureaucrat) memoir, the traumatic-childhood memoir, the substance-abuse memoir, the spiritual-journey memoir, the showbiz memoir, the spirit-of-place or vanished-era memoir, the illness memoir and the sexual-exploit memoir.

To name just one recent example of each, in order: "Taking Heat," by Ari Fleischer; "The Glass Castle," by Jeannette Walls; "Smashed," by Koren Zailckas; "Leaving the Saints," by Martha Beck; "Kiss Me Like a Stranger," by Gene Wilder; "When All the World Was Young," by Barbara Holland; "Stranger in the Village of the Sick," by Paul Stoller; and "The Surrender," by Toni Bentley, which sounds as though it might be a military memoir but is not.

Obviously, categories overlap. Sexual-excess memoirs often have a spiritual-discovery aspect to them, as do illness memoirs. Spirit-of-place memoirs often shade into the ethnic-identity memoir, which can, in certain instances, merge with the food memoir, as in "The Language of Baklava," Diana Abu-Jaber's memoir, with recipes, of growing up as the child of an American mother and a Jordanian father. (It should not be confused with "Lipstick Jihad" by Azadeh Moaveni, which is about growing up as an Iranian-American and does not have recipes.)

Some memoirs defy categorization. Where do you place John Falk's "Hello to All That," subtitled "A Memoir of War, Zoloft, and Peace"? The author, suffering from chronic depression, heads off to cover the war in Sarajevo carrying a year's supply of the antidepressant drug Zoloft stuffed into a tube sock. The book has a little bit of everything: military combat, a spiritual awakening and lots of prescription drugs.

If Grant had been born a century later, and had a smarter agent, he would have mined his eventful life for several titles: one on the alcohol abuse, a second on the illness and perhaps a third filled with wistful recollections of his hometown in Ohio. It would have made a strong entry in the "nostalgia for vanishing small-town America" memoir.

Neither the category, the premise nor the title can predict artistic success or failure. It's all in the writing. "When All the World Was Young," about growing up in the 1940's and 50's in Washington, does not sound especially promising. But Ms. Holland, a shrewd, witty writer, casts a sharp backward glance at America the day before yesterday, when fathers ruled with an iron fist, children memorized lots of poetry and a girl could take pride knowing that her hometown would be bombed first when the Russians let fly with the H-bomb.

I look forward to "The Guinness Book of Me," by Steven Church, an implausible-sounding memoir about the author's lifelong obsession with the Guinness Book of World Records.

One particularly fecund minor category is the bad-job memoir, which has brought out the bitter best in writers ever since George Orwell's "Down and Out in Paris and London." (Modern-style memoirs often turn out to have lengthy pedigrees, even the druggy ones, anticipated by Thomas De Quincey's "Confessions of an English Opium Eater," which was published in 1822.) Two brilliant examples are "A Working Stiff's Manifesto," by Iain Levison, and "Job Hopper," by Ayun Halliday.

Ms. Halliday, the author of an anti-travel memoir called "No Touch Monkey!," evokes the low-grade horrors of telephone solicitation, waitressing and minding the stuffed polar bears at a children's museum. Her misery resonates on that dismal frequency all too familiar to the overeducated, underemployed and undercompensated.

The Levison book, whose paperback edition carries the subtitle "A Memoir of Thirty Jobs I Quit, Nine That Fired Me, and Three I Can't Remember," makes Orwell's Paris period look like graduate school. Toiling in the kitchen of a bad bistro, Orwell may have experienced some discomfort, but he never found himself neck-deep in cold fish, shoveling for dear life, as Mr. Levison did on an Alaskan trawler.

I see no end in sight. The memoir infrastructure, at this point, rests on a broad, solid foundation. For some time, scholars have devoted serious attention to memoir and autobiography (sometimes conflated into "life writing"), some of them attached to think tanks like the Unit for Studies in Biography and Autobiography at La Trobe University in Australia and the Center for Biographical Research at the University of Hawaii.

A host of enablers has arisen, urging everyone who has not yet written a memoir to do so as soon as possible. "Your Life as Story," by Tristine Rainer, the director of the Center for Autobiographic Studies in Pasadena, Calif., is but one of many advice books for aspiring memoirists. Others include "Living to Tell the Tale," by Jane Taylor McDonnell; "Writing the Memoir," by Judith Barrington; and "Writing About Your Life," by William Zinsser.

Those who cannot write can always hire those who can. In a recent Forbes column, Daniel Seligman commented on the growing trend among big-shot executives to hire ghostwriters and pricey consultants to turn out vanity memoirs.

There's absolutely no need to wait, either. The average age of the memoir writer has been trending downward, quite sharply. Ms. Zailckas, the author of "Smashed," is in her early 20's, and Melissa P., the semi-disguised author of the erotic memoir "One Hundred Strokes of the Brush Before Bed," was a mere teenager when she wrote the book. A reader of this newspaper, responding to an opinion column on the proliferation of memoirs, wrote a letter to the editor announcing that she had created a memoir-writing workshop for her second graders.

When they get a little older, they may want to join one of the many memoir groups that have sprouted across the country, small collectives of aspiring memoirists who gather to talk about their lives and read their memoirs-in-progress to each other.

Their efforts may be as fundamental as breathing. John Eakin, an emeritus professor of English at Indiana University, has argued that human beings continuously engage in a process of self-creation and self-discovery by constructing autobiographical narratives. In a sense, we are the stories - multiple, shifting and constantly evolving - that we weave about ourselves, and this storytelling urge may even be hard-wired.

In a recent essay in the journal Narrative, Mr. Eakin cites the case of a patient of Oliver Sacks's who suffered from severe memory loss. Most of his waking moments were spent reinventing himself, constructing one story after another, as the previous one faded from memory, setting off existential panic. No story, no identity. Everyone is writing a memoir, all the time.

Almost a decade ago, James Atlas, in The New York Times Magazine, proclaimed the age of the memoir. Then he posed a question. Can it last? "Will memoir prove as evanescent as other cultural phenomena?" he asked.

Apparently not, since he just published his own memoir, "My Life in the Middle Ages." It's about being middle-aged. That leaves plenty of time for at least one sequel.

When Me Is the I's Favorite Subject

The current memoirs in the Critic's Notebook article, in the order mentioned.

'CALLGIRL: CONFESSIONS OF AN IVY LEAGUE LADY OF PLEASURE,' by Jeannette Angell. Perennial Currents/HarperCollins. $26.

'BAT BOY: MY TRUE LIFE ADVENTURES COMING OF AGE WITH THE NEW YORK YANKEES,' by Matthew McGough. Doubleday. $22.95.

'ROLLING AWAY: MY AGONY WITH ECSTASY,' by Lynn Marie Smith. Atria/Simon & Schuster. $24.

'ALL IN MY HEAD: AN EPIC QUEST TO CURE AN UNRELENTING, TOTALLY UNREASONABLE, AND ONLY SLIGHTLY ENLIGHTENING HEADACHE,' by Paula Kamen. Da Capo. $24.95.

'FAT GIRL: A TRUE STORY,' by Judith Moore. Hudson Street Press. $21.95.

'I'M NOT THE NEW ME: A MEMOIR,' by Wendy McClure. Riverhead Books. $14.

'FAITH IN CARLOS GOMEZ: A MEMOIR OF SALSA, SEX, AND SALVATION,' by Samantha Dunn. Holt. $23.

'HOUSE: A MEMOIR,' by Michael Ruhlman. Viking. $24.95.

'TAKING HEAT: THE PRESIDENT, THE PRESS AND MY YEARS AT THE WHITE HOUSE,' by Ari Fleischer. William Morrow. $26.95.

'THE GLASS CASTLE,' by Jeannette Walls. Scribner. $25.

'SMASHED: STORY OF A DRUNKEN GIRLHOOD,' by Koren Zailckas. Viking. $21.95.

'LEAVING THE SAINTS: HOW I LOST THE MORMONS AND FOUND MY FAITH,' by Martha Beck. Crown. $24.95.

'KISS ME LIKE A STRANGER: MY SEARCH FOR LOVE AND ART,' by Gene Wilder. St. Martin's. $23.95.

'WHEN ALL THE WORLD WAS YOUNG: A MEMOIR,' by Barbara Holland. Bloomsbury. $24.95.

'STRANGER IN THE VILLAGE OF THE SICK: A MEMOIR OF CANCER, SORCERY, AND HEALING,' by Paul Stoller. Beacon. $23.

'THE SURRENDER: AN EROTIC MEMOIR,' by Toni Bentley. ReganBooks/HarperCollins. $24.95.

'THE LANGUAGE OF BAKLAVA: A MEMOIR,' by Diana Abu-Jaber. Pantheon. $23.

'LIPSTICK JIHAD: A MEMOIR OF GROWING UP IRANIAN IN AMERICA AND AMERICAN IN IRAN,' by Azadeh Moaveni. PublicAffairs. $25.

'HELLO TO ALL THAT: A MEMOIR OF WAR, ZOLOFT, AND PEACE,' by John Falk. Holt. $25.

'THE GUINNESS BOOK OF ME: A MEMOIR OF RECORD,' by Steven Church. Simon & Schuster. $23.

'A WORKING STIFF'S MANIFESTO: A MEMOIR OF THIRTY JOBS I QUIT, NINE THAT FIRED ME, AND THREE I CAN'T REMEMBER,' by Iain Levison. Random House. $11.95.

'JOB HOPPER: THE CHECKERED CAREER OF A DOWN-MARKET DILETTANTE,' by Ayun Halliday. Seal Press. $14.95.

'YOUR LIFE AS STORY: DISCOVERING THE "NEW AUTOBIOGRAPHY" AND WRITING MEMOIR AS LITERATURE,' by Tristine Rainer. Tarcher/Penguin. $14.95.

'LIVING TO TELL THE TALE: A GUIDE TO WRITING MEMOIR,' by Jane Taylor McDonnell. Penguin. $14.

'WRITING THE MEMOIR: A PRACTICAL GUIDE TO THE CRAFT, THE PERSONAL CHALLENGES, AND ETHICAL DILEMMAS OF WRITING YOUR TRUE STORIES,' by Judith Barrington. Eighth Mountain Press. $14.95.

'WRITING ABOUT YOUR LIFE: A JOURNEY INTO THE PAST,' by William Zinsser. Marlowe & Company. $23.95.

'ONE HUNDRED STROKES OF THE BRUSH BEFORE BED,' by Melissa P. Grove. $12.

'MY LIFE IN THE MIDDLE AGES: A SURVIVOR'S TALE,' by James Atlas. HarperCollins. $25.95.