NEW YORK, NY.- Sheila Sullivan turned 86 this summer, and she had aging on her mind, because she was genuinely curious. What do all those old people you hear about, those poor souls, do with themselves all day? She had no idea.

“I’m much too. …” and there was a pause, like in the theater, “whatever-it-is, to be old,” she once told me.

Sullivan is an actress whose resume begins in the Atomic Age and traces the history of late-20th century Hollywood and all its ups and downs like a line on a healthy EKG scan. A couple of Tuesdays ago, she stepped out in style with Tina Dupuy, a writer and her former neighbor who has been a close friend for 10 years. They arrived at Radio City Music Hall to see the Rockettes. It was, remarkably for Sullivan, who has seen everything, her first time.

“I wanted to be one!” she recalled recently. She showed up one day in the 1960s for Rockette auditions. “I’m about this much too short,” she said, her hands stacked as if describing a tall sandwich. “When I wasn’t in the show, I didn’t see a reason to see it.”

For whatever reason, West 50th Street was closed to traffic, so the two friends did a little dance in the middle of the street, Sullivan clad head to toe in a leopard-print hat and coat.

“It caused a riot inside,” Dupuy said. “Women just stopping her to tell her she’s gorgeous.”

Sullivan thought the show was wonderful. “I’m not upset that I’m not the star of something,” she said. “Much.”

This asterisk-added modesty follows a life and career edited here for space: a Broadway actress who worked alongside Woody Allen and Sammy Davis Jr. A dancer at the Tropicana in Las Vegas. An activist marching for civil rights alongside Black celebrities in Selma, Alabama, in 1965.

The wife of a theater publicist, later divorced, and then the wife of television star Robert Culp, later divorced. That was enough of that. Stick a fork in a toaster once, it’s an accident. Twice, maybe you weren’t sure what the heck just happened. Three times? You’ve got problems.

And most recently, Sullivan was an Upper West Side renter fortunate enough to have had the right neighbor when trouble arrived.

Earlier this year, she had a scare, one familiar to many New Yorkers, famous or otherwise. An eviction notice appeared on the door of her apartment of 40 years.

That’s when her former neighbor in the building, Dupuy, stepped in. The two had become inseparable over the years, flitting in and out of Broadway shows and movies and relaxing at their regular spot for cosmopolitans.

I met the women as they untangled the bureaucratic errors behind the eviction notice. Soon enough, the problem was solved. Five months later, Sullivan can say that she is no longer the panicked woman who was having nightmares of being put out on the street.

She’s back to doing what she’s good at. Being Sheila Sullivan.

In November, she and Dupuy were invited to a party for Nat Horne, 93, who, like Sullivan, had appeared in “Golden Boy,” a 1964 musical about a boxer played by Sammy, as everyone knew him. Horne was a member of the ensemble, and Sullivan was an understudy who was called on short notice to perform, months into the run.

Every now and then, of course, things that happen to regular folks happen to Sullivan. She and Dupuy caught terrible colds in November and recovered. Around the same time, Sullivan, who still exercises with the stretches she learned while dancing, pulled a muscle that caused such pain that she had to be taken to an emergency room.

What happened? the doctor asked.

Obviously: “I was doing ballet.”

She recovered and resumed her stretches, a bit more carefully. So maybe there is something to the whole aging thing?

Or not.

“I’m old,” she said. “But I’m not old.”

The morning after the Rockettes show, the two laughed about their night, and their year together, over breakfast at Dupuy’s apartment.

“This woman is extraordinary and I wanted to share her with the world,” Dupuy said. “I thought that the only way I would be able to do that was with her obituary.”

Sullivan laughed: “Thanks!”

This article originally appeared in The New York Times.