I’m keeping my nails ridiculously short these days. It’s partly because I am playing the piano again, and partly because getting my nails done bores me. I am at the point in life when I don’t want to waste my time. And I am not trying to impress anybody.

There is a fairly thin line between feeling free to do what you want and letting yourself go. It’s a much thinner line for women than for men. Gray-haired men look distinguished. Gray-haired women usually just look old. I have a friend who decided to stop coloring her hair, and she looks fabulous. Not everyone does.

Most days, when I am at home writing, I still do my hair, wear mascara, and make an effort to look nice. I partly do it so my husband isn’t horrified (not that he would ever say so, even if he was). But I mostly do it for myself. I feel crummy all day if I don’t make some effort, even if it’s not all that noticeable to anyone else.

I have two particular women I always keep in mind as examples. One is someone I knew quite well. She was a friend of my mother’s who lived to be 108. Her name was Blanche, and I got to know her as an adult when we were both docents at a tiny art museum. Even though we worked together, I never dared call her by her first name; it would have been disrespectful. She was an alert and intelligent nonagenarian, and every time I saw her—even at her own home—she was nicely dressed, wearing a touch of makeup and a little bit of jewelry, and looking nicely pulled together. She was never overdone. But she took care.

The other is someone I never even met. Some years ago I was invited to speak at the opening of a museum exhibit. I only knew the curator and some of the museum staff, so after I did my part, I had the pleasure of carrying a glass of champagne while I wandered alone in a gallery of Dutch masters. This, I confess, is just about my favorite thing to do in the world, and I rarely miss an opportunity to hang out at the National Gallery. It soothes me.

But, as usual, I digress.

On my rambles, I noticed an elderly lady being shown around the gallery by one of the museum staff. He was attentive. She was clearly interested. She looked carefully. She asked questions. She spent more than the polite amount of time with the paintings. She was slim, white-haired, and elegantly dressed in black. She projected both strength and grace, while also being impeccably stylish. I asked who she was. She was Roberta McCain, John McCain’s mother.

Later, as I waited for a cab, I watched as one of the valets brought up a tiny hatchback. He handed the keys to Mrs. McCain, and she drove off alone. I don’t know exactly how old she was then, but she, too, lived to be 108.

I think often of these two women: one a small-town girl in Wisconsin, the other the daughter of an oil tycoon, wife of an admiral, and mother of a war hero and senator. What was their secret? Genetics, no doubt, were a factor. But wealth clearly was not. Nor was a life without worry. What kept them going? Faith? Curiosity? Generosity? Friendship? Or just plain stubbornness?

I can’t help thinking that there is a connection between longevity, having interests in larger things, and a willingness to make an effort. And so, I continue to try. I think it is a signal to yourself that you are worthwhile, and that you are not idling somewhere in a back room. You are prepared to meet the world. You are in the world. That matters a lot, I think.

But I also wonder whether art museums are a wellspring of long life. It’s a theory I am happy to test. Any time.