Old age is not a subject one usually talks about around the dinner table — unless everyone around the dinner table is equally old. Then the conversation is interjected with jokes.

Old age conversation usually turns into an organ recital. I never buy green bananas anymore.

This can temporarily reduce the anxiety of wondering what is ahead of us. But the anxiety often returns when we are alone with our thoughts. We all know how it will end — the worry is in not knowing when it will end.

Fortunately, there are a lot of people on the Vineyard who haven’t reached old age yet (and even a few who have) but who are looking ahead, perhaps with some alarm, to that time. When my generation is gone — and many of them are already gone — the problem will be the huge number of baby boomers who will need care. They might need downsizing, as I did, from a five-bedroom house to a one-bedroom apartment on one floor. They might need transportation to doctor appointments, shopping trips, or transportation to a dinner party or a movie. We already have in place a few organizations to solve some of the problems elders might face on the Vineyard. But the biggest problem is beginning to hit the front pages of our two weekly newspapers — affordable housing and elder housing.

Right now the choices are: 24/7 home care, Windemere residency, off-Island nursing home, or moving in with a family member. I turned 91 on Thursday this week, and I am one of the lucky ones. I had the money to build a small apartment onto my oldest daughter’s house, right around the corner from the home I had shared with my husband for more than 50 years and had raised my children in. In 2008, I was 82 and finding it difficult to care for my 88-year-old husband. He moved into Windemere and I lived alone in the large house by myself for three and a half years, learning to handle electricians, plumbers, carpenters, etc. until I felt I couldn’t cope anymore. In 2012, after Johnny died, I moved into my apartment at Deborah’s house. I was 86 and was having trouble walking and breathing at the same time.

As Ellen Goodman said: “It had begun to occur to me that life is a stage I am going through.”

I began to think of my long life as being divided into chapters — babyhood, toddler, student in school, high school, college, and then marriage. A life with husband and children, a lovely home in a small town on a small Island. Then there were 20 years as a junior high teacher and three granddaughters, all born and brought up in West Tisbury. They are grown now, launched into their own adult lives.

And I now realize I am into the last chapter of my own life.

I think about other forms of life and how they develop into their adult forms. Elephants and tortoises live as long as we do, and sometimes longer. Cats and dogs live much shorter lives. It is the insects that seem to have the strangest life spans and their changes are much more peculiar than ours. I have only studied the life cycle of the Monarch butterflies, and it has raised some interesting questions in my mind.

The monarch butterfly starts as a tiny egg hidden on the underside of a milkweed leaf. After about a week it changes into a larva, the familiar green and yellow caterpillar we might see chewing its way through the milkweed leaves. When it matures, the caterpillar attaches itself to a twig or branch, sheds its skin and wraps itself into a chrysalis, lovely in lime green with golden touches here and there. A veritable jewel.

There it hangs as magical changes take place inside, hidden from the eyes of observers, and after about two weeks it emerges as an orange and black butterfly. It is as if the caterpillar has changed in every way into another being by the time it emerges as a butterfly.

Then I think about the development of a human being. An egg and a sperm unite and turn into a fetus that grows and develops into a live baby in nine months. The baby develops into a child and then an adult and lives up to 100 years before it dies and turns into — what?

As I celebrate my 91st birthday, it is with the knowledge that a new generation will soon emerge in our family. A little child, born to Caroline and Daniel, will become a 13th generation Mayhew to be born and raised on Martha’s Vineyard. This child will make me a great-grandmother, something I never imagined I would be.

My last chapter is proving to be a good one — I am living close to my eldest daughter who is a loving caregiver, my home is now of manageable size for one person, all the members of my family but one live in West Tisbury, I am surrounded by friends, some of whom I have known since childhood, and I am relatively healthy.

I am thankful.

Shirley Mayhew lives in West Tisbury and contributes frequently to the Gazette.