In 2015, New York Times reporter John Leland set out to find six super seniors for “85 & Up,” a series profiling one of America’s fastest-growing demographics. To his great surprise, the yearlong assignment ended before it got old.

“I initially thought, I can’t give these people up,” says Leland, who’d admired Tuesdays with Morrie, Mitch Albom’s inspirational account of visiting with a wise elder, before experiencing some of the same graces. “[Albom] was somehow transformed by these lectures that he’d gotten from his old professor, and my experience was no less profound than that.”

Searching senior centers, nursing homes, home care agencies, and the internet, Leland arrived at six subjects through whom he presents a caring, compassionate, and diverse picture of late old age. They are: Fred Jones, Ping Wong, John Sorensen, Helen Moses, Ruth Willig, and Jonas Mekas—each with fascinating stories to tell, imparting crucial lessons in Happiness Is a Choice You Make: Lessons from a Year Among the Oldest Old.

“Each elder had different lessons to teach:” Leland writes, “from Fred, the power of gratitude; from Ping, the choice to be happy; from John, the acceptance of death; from Helen, learning to love and be needed; from Jonas, living with purpose; and from Ruth, nourishing the people who matter.... I wasn’t blazing new ground, but rediscovering some ancient connections. The blazing part was how happy the lessons made me, and how I wished I’d learned them earlier.”

At the time, Leland was 55 years old, recently divorced, living alone for the first time in decades, and responsible for the care of his 86-year-old mother, whose health and mobility issues had her contemplating suicide. Weekly visits with Jones, Wong, Sorensen, Moses, Willig, and Mekas (and an improvement in quality of life for his mother, to whom the book is dedicated) changed not only the way Leland looks at advanced age but the way he lives today.

“I’ve been a Gloomy Gus for most of my life—my friends would tell you that,” he says, “but this really made me 100 percent more optimistic about the world and [late old age].

“Going into it,” he says, “I thought old age was just decay without compensation. Now I think, what are the things that give me pleasure? Other people, the arts, being creative, having a purpose in what I do. Why couldn’t I have those things at 85? I’ll be different, a little bit slower, but winning in tennis has never been how I measure myself, and won’t be when I’m 85.”

As Kirkus writes in a starred review of Happiness Is a Choice You Make, “Few books about aging show such clarity and purpose or so deftly blend clear-eyed examinations of social issues with a realistic but hopeful cast of mind.” To this end, Leland incorporates numerous scientific studies that point toward the potential for growth and fulfillment in late old age. This may be unimaginable to the uninitiated—for, as Helen Moses is fond of saying, “I was your age, but you were never my age”—but our elders often judge their lives more favorably than we might.

The best way to know is to ask them.

“Throw out all your preconceptions and just talk to people person to person,” Leland says. “We are all who we are, with all our limitations and abilities, whether we’re 18 or 68 or 88. We all share many, many things in common, and we all have our differences. The interest comes in the tension between the two of those.”

Megan Labrise writes “Field Notes” and features for Kirkus Reviews and is the co-host of the Kirkus podcast, Fully Booked.