He’s 101, Unless He’s Only 98. And He Just Wrote Another Novel.

WESTPORT, Conn. — A.E. Hotchner, the man who was everybody’s best friend — Ernest Hemingway’s, anyway, and Paul Newman’s — wrote his latest book in longhand. He did not let his wife, Virginia Kiser, read the manuscript as he went along.

She would peek over his shoulder, or try to. He would cover the words with his other hand.

She said, from across the room.

The book, “The Amazing Adventures of Aaron Broom,” is a novel about a 12-year-old boy named Aaron in St. Louis, by a writer named Aaron, who grew up in, you can guess where. It begins on June 28, which is guess-who’s real birthday.

Young Aaron has a way of being in the right place at the right time, and making the right connections with the right people. That makes “Aaron Broom” sound like a training manual for Hotchner’s life, which at so many turns was about the eventfulness of friendships.

Hotchner described “Aaron Broom” as a project to carry him through the year he turned 100, unless it was the year he turned a mere 97 — more about that later. “I wanted to make it a jolly affair,” he said of the book, “something that would celebrate the fact that you could get as old as I had gotten and, to my vast surprise, still have some of my pebbles on the beach.”

Now, again from across the room, came another revelation from Kiser: “Hotch had an eye removed three years ago.” During cataract surgery, he said. Actually, he still has the eye, but no sight in it. Hemingway would be wearing an eye patch if it had happened to him, no doubt.

About those friendships. Hotchner knew J.D. Salinger (in Greenwich Village, before Salinger moved to New Hampshire) and Tennessee Williams (in college, when the not-yet-famous playwright went by Tom). And writers like David Halberstam and Gay Talese. And editor Nan A. Talese, who published “Aaron Broom” this July (and is married to Talese). And the crowd from Elaine’s, the Upper East Side celebrity hangout that was as much a salon as a saloon before it closed in 2011. He was also was present at the creation of the vat of salad dressing that inspired Newman’s Own. Hotchner had met Paul Newman when he worked on an adaptation of the Hemingway story “The Battler” for television in the fall of 1955. The star was to have been James Dean, but he was killed in a car crash less than a month before the program was to go on the air, live, on NBC. Newman was cast to replace him. The New York Times’ review of the program said Newman “had to surmount grotesque makeup, but was quite effective.”

He and Hotchner both bought houses in Westport in the 1950s. The salad dressing came along later — Newman would make a batch at the holidays, pour it into wine bottles and drive around the neighborhood, leaving bottles at friends’ houses. At holiday time in 1980, he called Hotchner, and together they made an unusually large batch, so much they had to find something to stir it with. Newman came up with a canoe paddle. They also came up with the idea for a company that would sell salad dressing and give the profits to charity.

As for “Aaron Broom,” Hotchner had written biographies of Doris Day and Sophia Loren, musicals with Cy Coleman, a novel called “The Man Who Lived at the Ritz” — and a memoir of “Papa Hemingway,” about his years as a loyal but not particularly obsequious companion and confidant to the hard-living writer. But he had never written a murder mystery, and that was what he said he had in mind: a murder mystery set against the background of a boyhood disrupted by the chaos of the Great Depression.

He had already written a memoir about such a boyhood, “King of the Hill,” published in 1972. It was made into a movie, released in 1993, that was directed by Stephen Soderbergh, by then famous for “Sex, Lies and Videotape.”

The father in both books is struggling to sell watches in the Depression, the family home is a couple of rooms in a hotel that has seen better days, the family car is in danger of being repossessed. In both, the father finds hope in a job through the Works Progress Administration.

But Hotchner did not just write the same book over again. “'King of the Hill’ was me as I sort of remembered myself,” he said. “This time I decided that I would improve him, let him be things that I wasn’t but would like to have been.”

So Aaron Broom “had more bravado than I ever had,” he said. Hotchner said he would not have broken into a woman’s apartment, as Aaron Broom did.

“Absolutely not,” he said. “That was too out of the ordinary of who I was. But I had lived life with bullies during the Depression. There was a big bully who was bopping me on the head, and with Aaron, I was able to put him in his place.” With, he said, a swift kick to a place that cannot be mentioned here.

Inevitably, a conversation with Hotchner turns to Hemingway. They met in Havana in 1948 when Hotchner was working for Cosmopolitan magazine, tracking down well-known people and persuading them to write something serious for Cosmopolitan. This was before Helen Gurley Brown. For the biggest name of all, there was the biggest topic: The future of literature.

Hotchner ended up sitting at Hemingway’s favorite bar, losing count of how many daiquiris they drank and becoming a protégé.

“I never felt in the 13, 14 years we had adventures that I was with Ernest Hemingway, in quotes,” he said. “He very early on assumed the role of a papa and enjoyed the fact that I was a dumb kid from St. Louis.”

Hotchner said he came up with the plan for “Aaron Broom” while lying in bed after celebrating his 100th birthday (unless it was only his 97th) He also hatched a timetable. He would finish it by the time he turned 101. Or 98.

“I thought, that is absolutely ridiculous, it’s too short a time,” he said. “I also thought, what the hell, it’s not a very complicated idea, it will give me something very forward-looking to do in what could be a rather depressing year. I sharpened up the pencil and started to go.”

As for his age, he was told when he was growing up that he had been born when “the troops, our troops, went over to Europe” in World War I. That was in 1917.

“My father was destined to go over,” he said, but was notified by the draft board that because there was a newborn in the household, he did not have to ship out.

“Over time, I traveled so much and lived so many places and had so many passports that the dates of birth got whacked,” he said. “Every time I needed a new passport, it came back with a different date. I was so fearful of being wrong with the passport because I traveled so much that I went along with the various dates, which went from ’17 to ’19 to ’20. Nineteen-twenty was on the reissue of a driver’s license. I figured, it’s an even number and nice to remember — why don’t I just take 1920.” Even though he was born three years earlier, he said, on June 28, 1917.

In the internet age, don’t tell that to some entries in Wikipedia or to IMDB, which enshrine 1920.

Don’t search for Aaron Hotchner, either. That is his name (the “E” is for Edward). But a search for Aaron Hotchner will lead to an entry for a character on the long-running CBS drama “Criminal Minds.”

“He was so up in arms” over a role with his name, Kiser said, “that he even got a lawyer, but nothing came of it.”

After “Aaron Broom,” what is next for the real Hotchner?

“I don’t know,” he said. “I like to say that was pretty much it, but nobody knows. Any writer will tell you, you don’t know.”