Water is an essential ingredient for the existence of life as we know it. Water is the only substance naturally present on the earth that exists in three distinct states — solid, liquid and gas.

In the water molecule, oxygen is the central atom. It has four pairs of valence electrons surrounding it.

Those words are lifted almost verbatim from a conversation with my husband in 1965 when we were dating. I glazed over. He continued on. I had no interest whatsoever in what he was saying but I loved that he cared about something with such passion. Even something I couldn’t understand. I loved the awe in his voice, the glint in his eyes and the fact that I knew he was smart. And then he slaughtered the subjunctive. He said “If I was.” I cringed and held my English teacher tongue. Despite the fact that he spelled zero with two r’s and I couldn’t name one element on the periodic table, we got engaged. When I mentioned the name of the jeweler where I wanted us to shop for my diamond, my intended, with the same fervor he used to describe the infinitesimal size of an atom, said “Nance I’m not buying into the De Beers conspiracy.” The who-what? is what I remember saying in response. He then explained blood diamonds and monopolies and manipulation of the market and children whose hands were cut off so I could have a diamond that was forever. Remember this was 1966. So we went to Maine for a weekend instead, a memory that I can’t wear on my ring finger but I have pictures of the rocky seacoast and us eating lobsters with greasy hands and happy grins.

When young people (Oh man, I never thought I would use the phrase about people other than myself) ask me how did I know when I’d found the right guy, my answer isn’t something you can write on a yellow legal pad. It’s a feeling. In your stomach. In your head. In your heart. But I do often say if he’s nice and he makes you laugh, grab him.

We named our first cat Electron.

In the 43 years we have been married, there have been more than three distinct states. In the early years when I was so insecure, I remember saying something like “tell me you’ll never leave me,” imploring, maybe even begging. I didn’t say it just once. It was like a mantra in those early years. And his very unemotional, level-headed answer was always the same: Nance, I don’t know what’s going to happen in life. I don’t want to make a promise I can’t keep. And if you were a fly on the wall you would have seen various states of solid liquid and gas erupting from my soul, the part of me with The Big Abandonment Issue. I would scream, then lie to me! But he wouldn’t. In about our 25th year, I remember exactly where I was standing in the kitchen when my husband looked at me and said: “I could never be married to anyone else.” And before I could hear myself saying the words, in a very unemotional and level-headed voice I said: “You can’t really say that. You don’t know what will happen in life.”

There was a beat and then a yelp. Wow, babe, I said. We switched places. Is that what happens? You become the other person?

The answer is no, but you do sort of adopt each others’ neuroses and help heal each others’ wounds. These days I think of love as a spackling compound. You fill in the broken parts, you smooth over the fissures, you cover the cracks in the walls. They’re still under there but they’re not so glaring. And if the marriage is good, you can paint over the bumps with luminous pastels.

Something interesting does happen in a long marriage, though. In the middle of the brown spots and the wrinkles you can still see the young face of your beloved. I swear on a good day when I am remembering to love him properly, he looks 26 and I can see him in that phony madras shirt from Sears (it was not 100 per cent cotton and would not bleed), the shirt he was wearing on the first day I met him.

And now he uses the subjunctive as if it were his native language and one of these days you’re going hear me say something like “Yeah. Water. It’s the only substance naturally present on the earth that exists in three distinct states.”

That’s when you’ll know we’ve reached marriage nirvana.

Nancy Slonim Aronie is the author of Writing from the Heart (Hyperion/Little Brown) and is the founder of the Chilmark Writing Workshop.