Fifteen years ago, having said all my life that I never wanted a baby, that I couldn’t fathom why any free woman would do such a thing to her body and her mind, I suddenly and passionately wanted a child. I remember where I was when this feeling, so heretical to me, arrived: it was early morning in London, and having come down Fleet Street on my way to work, I was standing at the till of a newsagents to pay for a Diet Coke, a flapjack and a pack of Silk Cut. There were no children there and no pregnant women; nothing had been said or done to change my mind. It had simply landed on me, and more or less immediately – because I’ve never known how to control an impulse, and because I was 30, which seemed to me then a great age – my husband, Robert, and I set about trying to have a child.

When for some months nothing happened, I turned to the websites where women who’ve never met scrutinise their bodies for signs of pregnancy or fertility or miscarriage, and my vocabulary changed. I became able to communicate in acronyms impenetrable to anyone who hadn’t held a dozen ovulation sticks in a dozen urine streams, and it is all so long ago now that I only remember one: 2WW. At first I took this to be some dry reference to the second world war, since they did seem to be always in battle, these women, or in flight – but in fact it refers to the “two-week wait”, the fearful, hopeful days between sex and ovulation, and the first signs the uterus had succeeded or failed (that these signs can be identical sometimes invokes a kind of madness, to which I also briefly succumbed).

During this time, I began to picture myself raising a boy as sweet and funny as my husband, and became prone to sentimental visions; one morning I imagined a row of small socks drying on a radiator and burst into tears. My desire to conceive became equal to my prior horror of conception, and when I failed to become pregnant I was indignant, as if for the first time in my life I’d flunked an exam. When eventually I did conceive, it was soon after my mother-in-law, Jenny, had died quite suddenly, and it seemed a recompense for our grief – both my husband’s and mine, and that of his father, David, who’d been not only Jenny’s husband but her carer during a life made difficult by rheumatoid arthritis. That pregnancy was only brief, and I’ve few memories of that time – though I do recall once lying in Victoria Park, east London, and lifting my shirt to allow the sun to reach my belly, saying “there we are – there we are!”, patting the skin over my womb and basking with my child in the late-afternoon light. I quickly miscarried, and for some days sat on the upper deck of London buses weeping steadily, to the visible sympathy of fellow passengers.

Subsequent investigations diagnosed unexplained infertility, and IVF was indicated as our likeliest route to parenthood. But already the surge of maternal longing was fading, replaced by sober consideration of what fertility treatment entailed. I was by then pursuing a full-time PhD during full-time employment, while writing my first book: there seemed insufficient hours in the day for hospital appointments, and injections, and whatever undignified tinkering about with my fallopian tubes they’d deem necessary. With horror I understood that I wanted to publish novels more than I wanted to raise a child – or at any rate that I wanted to write more than I wanted to endure years of interventions that might not produce a baby, but would almost certainly diminish my capacity for study. I pictured those small white socks drying on the radiator, and that was a lovely image – but I also pictured, down the other path, a room with sunlight illuminating ranks of books and a glass of wine and possibly a telescope, and it was as desirable to me as a nursery might be to another woman. One afternoon, over gin and tonic, I announced to a friend (herself happily a mother) that we’d decided not to pursue fertility treatment, and she grasped my hand: “Congratulations!” she said, “I’m just as pleased as if you told me you were pregnant!” – a piece of understanding for which she’ll be forever loved.

What that friend knew – and what she’d always let me say – was that until that startling moment on Fleet Street, I’d always regarded the wanting of children, and the having of them, to be absolutely insane. Possibly you’d imagine this makes me a cold sort of person, who flinches from children on public transport and dines on the olives in her martini. In fact, I resemble an illustration of, say, a motherly badger in a children’s book: I’m sturdy and broad-hipped, flour frequently dusting the hem of my pinafore; I make patchwork quilts, windfall jam and my own pastry. I never met a baby I didn’t love, and though I’m not good with children (I’m incapable of silliness and don’t know how to play), I like them no more and no less than any other living soul, that is: according to their merits. Nor do I dislike mothers. Some of my best friends are mothers, and their children are my friends, too (for this reason I call myself childless, which represents mathematical fact, rather than child-free, which casts children of whom I’m very fond as burdens).

The trouble is this: I began to observe motherhood when very young and with the fascination of an anthropologist. As family members began producing their babies, I was aghast: never could I imagine actually choosing such a state. Familiar girls became haggard women who wept as their children screamed upstairs (these were the days when it was fashionable to abandon babies to their sorrow); familiar homes became tautly silent in case the mercifully sleeping infant was woken by a footstep; marriages were strained to snapping by insomnia, and by a deadening of spirits I later recognised as postnatal depression, or the effects of a hopeless co-parent. In time I watched with equal confusion as women willingly gave up their pursuits and careers and – at their own estimation, not mine – their identities, consumed by atavistic emotions that caused them to abandon their most basic needs. One friend became painfully thin, having failed to eat enough to compensate for the demands of breastfeeding; another went about with her blouse transparent with leaking milk, and told me her nipple had a wound that could accommodate a two-pence piece, “just like a slot-machine!”

Then there was the contradictory mental state that seemed to me to entail the loss of reason: mothers declared they’d never felt so wretched but also never so fulfilled; none ever suffered like them, but equally (and at precisely the same time!) none ever knew such happiness. Motherhood was a maligned and undervalued condition, but also it was an exalted state that almost every woman I knew either anticipated as inevitable, or sought with a desperation that left their sanity and bank accounts depleted. My attachment to logic and reason – better suited to a mathematician than a novelist – caused me to view all this with a sort of bewilderment, as if I were a student who couldn’t solve an equation.

It occurs to me now that I underwent a kind of neurological version of the social media algorithms that turn an idle interest into an obsession: I’d clicked on unhappy mothers early on, and for decades could see little else. Perhaps because I had no dog in the race, new mothers confided in me, and I found that common to them all was guilt: endless, particular, and to my mind nonsensical. Guilt if the baby was not breastfed, but then again guilt if it was breastfed only for three months, or six months, or 12; guilt if the birth was caesarean, or assisted by any of the interventions for which millennia of women would have given their right arm; guilt if the child would not eat peas, or would eat only peas, or was left unattended and put a pea up their nose. “What I would like,” I often said, “is to be a father”, noting how often men (their bodies and careers intact) would regard their partners with simpering gratitude and say that, really, it was all down to her, concealing within the compliment a refusal of such indignities as, for example, the daily preparation of a packed lunch.

Above all (it is this that causes me to feel most shamefully unnatural), I feared not that I would be forced to abandon my fierce literary ambitions in service of my child, but – far, far worse – that I would actually want to.

Soon I will be 46. I never did conceive again: I never will. I have the study of which I dreamed – I have a piano, a telescope, a microscope and a little printing press; my many thousand books flank an open fire, and my time is largely my own. I never grieve my lack of children, but now and then I wonder how things might have been, had I, as that watchful and too-rational child, seen not motherhood’s troubles, but its joys. Once, overlooking the river that divides Namibia from Angola, I ate lunch with a clever and vital woman whose merry nature seemed not contrary to her motherhood, but part of it – she loved her children and she loved her work: it was as simple as that. To the mortification of us both, I burst into tears: “If I’d known you when I was young,” I said, “I might be a mother now – but you see: I had no idea I could have been happy!”

Still, over the years I’ve felt various kinds of fiercely protective and effortless affection, as if maternal feeling sometimes caught up with me, an animal I never quite outran. I’m fortunate to have godchildren, and innumerable nieces and nephews; one of these – though considerably smarter than me and gainfully employed at the British Museum – still calls me “Auntie Sarah”, and I’ve never asked her to drop the honorific, since the tie of blood is precious. Some years ago, a tall, coltish girl from the American south arrived at the house to look after our sensitive rescue hound, and never quite left. Her cleverness showed itself in a thousand surprising and sometimes ludicrous ways; she bred fancy mice that resembled animated pearls, occasionally modelled, and painted beautiful representations of fish guts. Immediately I liked all these things about her, and felt I would have liked them very much in any daughter of mine; these days I suspect my house is as familiar to her as her own, and if you asked me to explain why I love her, I could say only that I like having her about the place. When recently she said, more or less in passing, that since she disliked the idea of speaking at my funeral when the time inevitably came, there was nothing for it but to train as a stonemason, in order to carve my tombstone, I only said “very sensible”, and concealed tears as best I could.

And then, in the autumn of 2023, I experienced a curious echo of that time when I’d briefly tried to have a child, as I encountered the NHS policy of leaving patients with suspected cancer for no longer than two weeks before seeing a specialist: another “two-week wait”, if sometimes at the other end of life. David, my father-in-law, having previously seemed in good health, was found to have a suspicious growth in his oesophagus: cancer was suspected, and would be confirmed within 14 days. So his two-week wait ticked away in the bungalow where he lived, as he put the kettle on and made himself porridge he could never quite eat, and set about phoning friends and family members to give them news that was not quite news, because it would be two weeks before the possible became certain. Then the possible did become certain: cancer was confirmed, and he lived for just less than nine days. Those days consumed my husband and me, as we nursed David to his death in his own sitting room, stunned by the speed and rapacity of the disease. There were no hours then but those hours, no world but the bungalow, no object but a dying man’s comfort – and often it occurred to me that we performed our acts of care with something like the instinctual, loving competence of a new mother.

Now, those two times of waiting have got muddled up for me – 14 days until signs of life, or the possibility of life; 14 days until signs of death, or the possibility of death. And in the many fortnights since then, I’ve often thought that in fact those days were really no different from any other days – that David and Robert and I had always lived with the possibility and even the proximity of death, as well as life, and that what had changed wasn’t the land, but the view.

• Death of an Ordinary Man by Sarah Perry is published by Jonathan Cape. To support the Guardian order your copy at guardianbookshop.com. Delivery charges may apply.