I lost mine six months ago when I could no longer care for my husband’s advancing dementia and sent him into care. Well, maybe I really lost it a couple of years before that, but I didn’t know it then. He was here, sleeping in the same bed, eating at the same table, sitting at the same desk — a living, breathing presence, if not a fully present one. His mind wasn’t working so well, but the familiar body was fine, and his heart still tried to be what he had been. Until one day, he couldn’t and I couldn’t, and we both lost our lives — only he doesn’t know it.

We were close, but I wasn’t one of those women of my generation who was defined by her marriage, by her husband’s life and status. I had an independent life — friends, work, travel — and so did he. A couple of decades ago, Christopher Lasch described the family as a “haven in a heartless world.” For us, it was such a haven, but our lives in the “heartless world” enriched and enlivened that haven and were a central part of the strength of our marriage and our family.

Now, he’s gone — and so is the haven. And the world does indeed seem more heartless. Yes, I still have my work, which can distract me from whatever pain and anxieties may beset me at the moment. But notice the language: It “can distract me.” Not enliven and enrich me, but distract me. Worse yet, I can’t always do it, can’t summon it up as easily as I used to before Hank’s dementia took a core part of my life.

I tell myself that I need to give in to the feelings, but I’m not even sure what they are. A certain emptiness, maybe fear. But fear of what? I can’t say truthfully that I didn’t feel some relief when Hank was safely settled in his new home, some sense of freedom to reclaim my life when he didn’t need my attention so insistently. I was (still am) grateful not to have to rush home, after an hour or two away, wondering anxiously what I’d find when I opened the door.

Nor can I say that living alone is without its compensations. I don’t feel that yearning loneliness I hear others speak of; I enjoy the solitude of it much of the time; and when I get tired of it, I have friends and family to lift me out. But I’m aware that there’s an empty space — not outside, not in the bed or at the dining room table, but inside me — the space that Hank occupied for nearly a half century and whose presence there I’d come to depend upon.

Over decades as a psychotherapist (never mind living life), I’ve dealt with people suffering loss, read the literature on mourning, thought about Elisabeth Kübler-Ross’s famous treatise on the subject, and wrote a response to it that was both admiring and critical. I remind myself of what I know, tell myself I’m in mourning, to let the feelings flow until they work themselves out and I come to terms with the new reality of my life. But mourning a real death is quite different from mourning a living one. Whatever one believes about death — it’s a passage into a kinder world, it’s entry into nothingness, or anything in between — it’s still an undeniable fact. Death is finite; life, as we know it, is over. Yes, I know, people awaken with visions of visitations, but eventually we come to accept death as an end to life. But when the brain dies and leaves the body intact, there is no end.

A few days ago, I talked with a seventy-something man who spoke tearfully about his wife’s recent death and his awkward attempts at coping with his new life as a widower and single man. I left our conversation feeling sad for him — and also envious. At least, I thought, he knows what’s ahead; he knows the meaning of the word “widower.” But I’m a widow with a husband who’s alive; I’m a single woman with the responsibilities of a wife; I have a future, but I have no idea what it will be or how to get there; and if my husband lives much longer, we’ll go broke.

There, I’ve said it, the thought we dare not speak: My life would be easier if Hank had died. My impulse is to take it back, to wipe the words off the page, to retreat from the thought, pretend I never had it, and hope you’ll forget I said it. But it would be adding another lie to all those words written these days about the selfless caretakers who think nothing of sacrificing their lives to a loved person who exists but doesn’t live.

In truth, I know from others in the same situation, that I’m not alone — knowledge that comforts me, normalizes my feelings somewhat, or at least makes them less monstrous and me less guilt-ridden. And I also know that, as with every other complex part of life, feelings are never so simple. So there are times when I actually get frightened at the thought of his death, fretting about what, at 86 years old, would give my life purpose if I didn’t have him to watch over.

My rational mind tells me I have plenty to keep me busy and purposeful. But there’s nothing rational about dementia. I thought before I lived with it that I knew something about this disease of the brain. I’ve seen it, worked with people who were slipping into it, others who were caring for someone suffering it. I’ve heard the stories about the weird, nonlinear way the disease shows itself — the way it seems to wax and wane, the way a person can slip from seeming something close to his old self to a helpless child, unable to articulate even a simple thought, from calm to unreasoning anger, from believing his caretaker is his lifeline to the paranoid conviction that she wants to murder him. It’s why it’s so hard to grasp the fullness of dementia’s complexity, why it’s so easy to deny what we see before our eyes. But I know now that, even reading the most compelling descriptions in the literature, even listening to the most poignant anecdotes from caretakers, you don’t really know dementia until you’ve actually lived with an afflicted loved one. And maybe not even then.

I look away from those words, gaze outside my window and see the western half of the city spread before me: the hills that define San Francisco, the bay sparkling in the sunshine in the foreground of my vision, in the background, a fleecy fog drifting in from the ocean and partially obscuring the graceful beauty of the Golden Gate Bridge, the ships peeking out of the fog as they pass under the bridge and into the sunshine. I love this familiar, yet ever-changing panorama and, on a day like this, when it looks as if it’s been scrubbed clean, I never fail to remind myself that I’m among the fortunate of the earth to live in sight of it. But the mournful sound of the foghorns that gives warning to the ships coming and going echoes with the sadness in my heart.

And I wonder: Why, when I have an engaged daily life, do I feel like I lost it. I see friends and family; I’m captured by events in the social and political world; I have work — writing, painting; I’m engrossed in the novels I’ve been reading almost obsessively since my husband is gone. Yet all these, even the words on this page, seem a distraction from the box called “real life” — the box that frames Hank and the institution in which he now lives.

Not that my visits to that life offer much reward. The place is beautiful, like one of those expensive boutique hotels — extra-wide carpeted halls, closed doors everywhere, the kind of calm quiet that soothes the soul. But if you’ve never been in a dementia unit, you can’t really know what a Kafkaesque experience it is.

I walk through the door — locked on the inside so residents can’t get out — and the show begins: Edward who, no matter what time of day, sits in the same chair near the door, head bowed as if asleep. I have the fantasy that he’s there in the hope that proximity to freedom will get it for him, but as I walk by, I say simply, “Hi, Edward, how are you?” He looks up, a blank acknowledgment that someone has called his name, and his chin drops to his chest again. As I turn the corner to Hank’s room, I see Molly, pushing her walker ahead of her and saying, “I have to go.” I smile at her, say hello, and ask her where she’s going. She stops, seems to be trying to figure out an answer, then repeats, “I have to go,” and sets off down the hall intoning, mantra-like, the same words over and over again. Then, Anna, who recognizes me with the same greeting every time, “You’re Hank’s wife.” I reply that I am, ask how she is. She stands silently for a moment, then repeats, “You’re Hank’s wife.” A few steps further along, I encounter Isabel, smiling the vacant smile that’s often a familiar feature of dementia. When I greet her, she bursts into song in a glorious operatic voice. She, of all of the men and women who live there, gives testimony to the complexity of the human brain. She doesn’t remember her name, but she can sing whole arias without missing a beat; she doesn’t recognize her grown children, but every Sunday morning, when a pianist plays old Broadway show tunes, Isabel’s voice accompanies the music with the words intact.

And Hank? If he’s not in one of the scheduled activities, I find him on his bed, surrounded by hundreds of pieces of paper. “Hi, sweetheart, what are you doing?” I ask as I walk through the door. “I’m working on my book,” he says — a book originally designed for cooks, professional and amateur, who, when confronting a recipe that calls for some foreign, unattainable ingredient, can find a local substitute on its pages. He started this project years ago, maybe a year or two after he’d been diagnosed with what the experts at the University of California labeled, “age related memory impairment.” When I trained in psychology over four decades ago, we called it “senile dementia.” Now dementia has a whole new array of diagnostic names, most of them sounding more “scientific” but meaning the same thing.

Over the nine years since that diagnosis, what was once a book has grown to an unwieldy 600 incoherent pages — an alphabetical list in tiny, illegible handwriting that has no meaning. And as he obsessively counts the entries and the pages, he proudly tells whoever is in earshot that he has 3,000 entries under the letter “C.” Maybe it’s a senseless exercise, but I prefer to think that, as with Isabel’s singing, it offers some connection, however thin, to the man he used to be, and gives some meaning to his largely empty days.

He puts down the paper he’s holding, looks at me lovingly, and says, “You’re so beautiful.” I smile, kiss him, tell him I’m glad he thinks so, and that I love him. Then we sit silently. I get edgy and make conversation, telling him what I did yesterday, what I plan to do today, recounting a conversation with our daughter, whom he still remembers, with an old friend, whom he does not. But there’s no one on the other side to send the conversation ball back. I know he’s becoming aphasic, that words don’t come easily to him anymore, and I try to be patient. I start to speak again, and he interrupts to ask, “What time is it where you live?” Where did the thought come from? I tell him that I live just a couple of miles from him and that the time is the same. He looks puzzled, checks the clock on his dresser, and says, “So what time is it there?”

Tears fill my eyes, I have no words, and we’re silent again. Not the companionable silence we used to know, but an awkward, uncomfortably empty one — a reminder that what we once had is gone. Sometimes after 30 or 40 minutes of this, he looks at his watch and says, “I guess you have to go”; sometimes it’s I who say it. What does it mean when he says those words? Is he as uncomfortable as I am with the silence? Is he also looking for something to carry the conversation forward and finding his incapacity to do it so intolerable that he’s relieved when I leave?

It’s one of the great difficulties in dealing with dementia: No matter how well you knew the person before, you have no idea what he’s thinking now. But since it’s a basic human impulse to try to make sense of our experience, we interpret what we see to give it meaning. If, as I have, you’ve spent decades helping decode a patient’s inner life, it’s as automatic as breathing. But I have no idea what to make of the fact that he seems happy with my arrival but is never distressed by my departure, indeed, seems at times to want to hasten it.

We’ve been married nearly 50 years — half a century. I believed I knew him as well, maybe better, than I knew myself. But that was another person, another life. I’m not a stranger to the feeling that I’ve had several lives, some of them painfully difficult. And although I don’t like living with the inevitable wounds of age, I’d rather be here than reliving any of those earlier times, places and experiences. Good or bad, I know they were necessary to my growth, to the development of the person I’ve been in these last decades, who I am today. But dementia is all about decline, not growth, and whether living inside it, as Hank does, or being a companion to it, as I am, it’s nearly impossible to make sense of it. If anything in this life can puncture the fantasy that we have some control over our lives, dementia may be the ultimate reminder, not just of its unpredictability but of its incomprehensibility. And its absurdity.

When, before these last months, I thought about why it’s so hard for us to learn from the experience of others, I would have said that it’s because we live in a society built on the myth that we’re in control, a “can-do” society and a culture that believes anything is possible, that to be “forewarned is forearmed,” even that we can continue to extend our lives well into our second century with no cost, social or personal. While I still believe that assessment is true, I also now understand another truth. Even when someone tells us what to expect, we can’t know it. It’s not that we don’t or won’t listen. It’s that the child can’t make any real sense out of the changes in her developing body until she experiences them; the young can’t grasp the rigors and meaning of the life of the old; our own mortality is nearly incomprehensible, even when we’re facing it. But unlike other life-changing moments, the demented by definition can’t understand what’s happening to them, while those who live alongside dementia, know it, but can’t see inside it, therefore, can never fully comprehend it.