“Larry Kramer was a nice guy” . . . is not a sentence you’ll be reading much today.

The forefather of AIDS activism, who died Wednesday at age 84, was, by most accounts, an obnoxious firebrand whose unrestrained volatility helped save millions of lives. He owned that, and was proud of it.

That’s all true. But to me, Larry Kramer was a mensch, and one of the main reasons I’m working as a film and theater critic today.

He would not take that as a compliment.

Kramer initially contacted me in 2011 after I reviewed the heart-wrenching revival of his play “The Normal Heart” for my not-read-at-all blog. It was one of the earliest reviews I’d written, on Blogger, with the grabby headline: “ ‘The Normal Heart’ made me want to throw up.”

The critique was positive, but that sickening sensation was brought on by a gut punch of a show that would make anybody skip their dinner reservation at Joe Allen and call it a night. HIV-positive characters desperately fight for survival and respect, and suffer loss after loss.

A week later, on my first day as an intern at New Dramatists, a playwrights organization on West 44th Street, I got a call from a board member, Joanne Jacobson, saying, “My friend Larry Kramer wants to meet you.” She told me that Kramer was thrilled to see a young person affected by his play, which was already 26 years old then.

Kramer and his producer Daryl Roth invited us interns to an evening performance, and a subdued Kramer met us outside the Golden Theatre afterwards. Even at that point in his career, at a tireless 75 years old, the man was still handing out letters he’d written to departing audience members about the progress yet to be made on HIV/AIDS.

A few weeks later, Kramer, clad in overalls, gave us a three-hour writing workshop, and I still remember a lot of what he said.

He pushed for total honesty from all of us, arguing that everything else is BS. He flat out asked my friend Sam, “Are you gay?” — which was not a typical question Sam got from his Vassar professors.

He also revealed his greatest strength.

“I always knew I could make people cry,” Kramer said, admitting that he had other faults as a writer. Public Theater founder Joe Papp’s wife, Gail, ultimately helped a scattered Kramer shape “The Normal Heart” with her advice. She told him, “Make every scene a fight.”

During the most famous scene in the drama, the character Ned Weeks — a Kramer stand-in — comes home with groceries to find his AIDS-stricken lover, Felix, on the ground with no appetite. “You can’t eat the food? Don’t eat the food. I don’t care,” a crumbling Ned says as he throws items from the bag on the floor.

“Who would ever want any milk? You might get some calcium in your bones,” he screams, smashing the paper carton on the ground, shattering the audience. Kramer knew that direct emotions, not table manners and poetry, were the key to getting his message across.

Kramer asked what I wanted to do for a career. “Critic,” I said. “Poo!,” he replied, and told me the story of how a New York Times (and later New York Post) critic once derailed his prospects and confidence.

“I wrote a play called ‘Four Friends,’ ” he said of his revision of 1973’s “Sissies’ Scrapbook.” “Clive Barnes came to the show, and the next day his review said, ‘With friends like these, who needs enemies?’ ” The play ran for one performance, which was enough for Kramer to temporarily abandon the field.

Despite his loathing of critics, it was never lost on me that the reason he sought me out was because he — the king of full-throated, emotional writing — was persuaded by a review I’d written, well, emotionally. That one gesture convinced me I could do this job.

We kept in touch occasionally, using his characteristically blunt email address, larrykramerhello@aol.com, and he wrote me a recommendation letter for grad school. (I didn’t get in, which says a lot about my GPA.)

In 2012, he desperately wanted “The Normal Heart” national tour to come to Chicago, where I was living at the time. And Kramer suggested I “start a little activism out there about raising the heat on one or the other of these theaters! (without mentioning that I suggested it!)”

Twenty-two, I then asked how he, 76, was doing.

“I’m fine,” he said. “Working my ass off.”