“If you’ve seen one 80-year-old, you’ve seen one 80-year-old.”

I just encountered that saying — attributed by a doctor to his fellow geriatricians —  and it drives home the fact that stereotypes are especially misleading when it comes to the old old. Or, as Claudia Kawis, director of the 90+ Study, puts it (a little less pithily), “Variability really is the hallmark of aging.”

The saying brought to mind New York Times photographer Bill Cunningham, the subject of a lovely documentary I saw last week. Born in 1929, Cunningham obsessively and artfully documents New York’s street fashion and high society get-ups – where couture and the proletariat meet up. His two columns, “On the Street” and “Evening Hours,” have been running in the Times since 1978. Thirty-four years! Two columns a week! Summer and winter, Cunningham snaps away all day, trotting down the sidewalk, straddling gutters, stopping traffic, and every night he attends a few of the countless parties and benefits at which he is a coveted guest. The choice is his.  He curries no favors, wants none, needs none. As Vogue editor Anna Wintour explains in the film, “We all get dressed for Bill.” Cunningham’s fashionisti are of every age and station (though textile mogul Iris Apfel, featured in this short film on the Advanced Style blog, is a favorite). His meticulously laid out spreads are witty and beautiful and grounded in deep knowledge. He attends Fashion Week in Paris each year “to educate the eye.” He shoots film, but has entered the digital era with a weekly narrated slideshow on the Times website.

Voices are so revealing, and Cunningham’s conveys his most appealing trait: boundless enthusiasm. “It’s mah-velous!” he declares, of ankle boots or Easter bunnies. He’s also astonishingly modest, shy, and kind, as I experienced firsthand a few years ago when I encountered him at his ur-haunt, the corner of 57th St and Fifth Avenue and asked if I could interview him. Behind that huge smile he bashfully demurred, and turned gently back to the battered Schwinn on which he pedals everywhere. What fuels that ever-present smile? A cheerful nature, for sure, and his delight and absorption in his work. Aside from the tyranny of deadlines, he has complete autonomy as an artist and journalist. He is the anti-nostalgist, delighting in new trends and outlandish get-ups that subvert the classics.

But much of what makes for a happy life for most of us is strikingly absent from Cunningham’s. He eats quickly and alone. He doesn’t join in the parties he chronicles.  He lives in a warren of file cabinets atop Carnegie Hall, from which he and the last remaining artist holdouts are being evicted. (The funniest moment in the movie is the realtor’s face as she tries to grasp his utter disinterest in any of the amenities her glossy rental has to offer.) He has a few friends but no intimate relationships, and in a poignant moment tells the filmmaker that he’s never had any.  “No time.”

In any number of ways Cunningham is an outlier.  For one thing, it’s a miracle he hasn’t been run over repeatedly. (No helmet, though he does wear a reflective vest at night.) Few people, even those with work they love, can enter their 8th decade capably, let alone cheerfully, without some kind of intimate assistance. Which just goes to show, if you’ve seen one 80-year-old, you’ve seen one 80-year-old.