I’M SENTIMENTAL; I admit that. No, not admit; I proudly declare that. After all, what’s so great about being unsentimental? What are the synonyms for unsentimental? Hard-eyed, hard-nosed, hard-hearted, hard-boiled. Realistic, phlegmatic, unfeeling. Do any of those appeal to you? Fancy sporting any of those on your T-shirt? Besides, scratch a cynic and you’ll find a sentimentalist beneath the paint. That’s as true here in no-nonsense New York as it is anywhere else. Maybe more so. Take my immediate neighbor, for example. She has the awkward name Agnetha Ogu. (The h is silent, the second g a sort of gulp.) She’s a second-generation immigrant. I find it difficult to guess her age and even more difficult to ask. She’s trim and brisk and works in some sort of IT business. The second time we met, I made a cautious inquiry about her origins.

She said, “I don’t have a past. I have a future.”

A few weeks later, when Christmas was looming, I invited her in for a drink. She looked around, trying to conceal her disapproval. (Most of my place is devoted to my work, so it looks like an explosion in an art-supply shop or a library. Agnetha’s apartment is clinical.) The blown-up and framed photograph of Win and Percy caught her eye.

“This is nice,” she said. “Who are these people? Do you know?”

I suppose she’d assumed that I’d bought the print in Greenwich Village or somewhere. I told her that they were my grandparents. I told her about Percy and the horses and the war. I told her about Win being widowed before my mother was born and how she’d spent her working life in a laundry. I guess I sounded very matter-of-fact — I was busy fixing our drinks. So I was surprised when I saw that Agnetha was touching the picture with the tips of her fingers and that she had wet eyes.

“I don’t have anything like this,” she said.

Sentimentality and nostalgia are closely related. Kissing cousins. I have no time for nostalgia, though. Nostalgics believe that the past is nicer than the present. It isn’t. Or wasn’t. Nostalgics want to cuddle the past like a puppy. But the past has bloody teeth and bad breath. I look into its mouth like a sorrowing dentist.

In the photograph, Win is sitting on a wicker garden chair and Percy is standing slightly behind her with his hand on her shoulder. She was proud of her long brown hair but knew that this was a vanity. So she wove it into a tight plait and pinned it severely to her head. She’s wearing a pleated floral blouse that fails to conceal the fact that she has a generous bosom. The expression on her face is hard to read. Consider, after all, that she had recently and reluctantly married; that she had traveled to a nearby city for the first time; that her husband was a foolish soldier; that although she’d thought this would be a very special moment, she’d waited in line for it; that the photographer was the first foreigner she’d ever encountered (an Italian called Delmonico); that she had been told to smile. She looks blank.

Percy is in the uniform of a private in the Norfolk Regiment. Presumably, he could have chosen to take the cap off, but he kept it on, perhaps because it made him look taller. I wish he’d taken it off. I try to imagine what he was feeling. He was a cocky farm boy who’d experienced the crushing brutality of military training. He has a possessive hand on the girl he’d pursued since childhood. He is wearing the king’s uniform and no doubt feels himself to be part of an important historic project. He is almost certainly scared, because, daft as he was, he knew that death is the soldier’s trade. He would have practiced bayoneting, stabbing sandbags hung from gallows. The peak of the cap shadows his eyes. Like Win, he is expressionless. The pair of them stare into the muzzle of Signor Delmonico’s camera, like people trying to maintain good manners in the face of some obscene species of horror.

I’m reading all this into the picture, obviously. Maybe they didn’t feel anything like that at all. There’s sentimentality for you.

On the other hand, there’s the fact that Percy is part of me. He’s woven into my DNA. We share cellular structure. He might be responsible for the shape of my nose, my dislike of cats, the color of my hair. He might have some genetic say in the kind of people I’m attracted to and the people who were attracted to me. And therefore he might be to blame for my failed marriage. Likewise, I might owe him my success, such as it is.

Win, too, of course. Her thorny string of cells is just as much a part of me. But I knew her; I never knew Percy. And, like Win, I am angry with him for marching off into oblivion. I deal with my anger by making up stories about him. By imagining him. By bringing him up a lost country lane between two vast peaceable horses, his hands between their bridles and their hot flat cheeks, to where my young grandmother leans on a gate.

I stole the photograph from my parents’ house in 1978, after Win’s funeral. It took them three months to notice it was gone.