I feel a sudden clear focus and perspective. There is no time for anything inessential. I must focus on myself, my work and my friends. I shall no longer look at “NewsHour” every night. I shall no longer pay any attention to politics or arguments about global warming. This is not indifference but detachment — I still care deeply about the Middle East, about global warming, about growing inequality, but these are no longer my business; they belong to the future. I rejoice when I meet gifted young people — even the one who biopsied and diagnosed my metastases. I feel the future is in good hands.

This is obviously not how I wanted things to turn out, but my wife and I have no regrets; we did everything I could to maximize my odds. And we want to thank everyone who has so graciously helped us. The really weird part of all this is that I'm not depressed. I'm not in denial (I assure you, I am fully aware of what is going to happen), nor am I whistling in the dark, but after having felt crappy and sick for 11 months, to finally be fully healthy again is so exhilarating that it's a wonderful emotional buoy. So I am going to enjoy each day very fully, and play hard with my kids until I can't.

But in the weeks after I learned that the breast cancer I have been in treatment for over the past year had spread to my bones — breaking my spine and becoming incurable and most likely fatal — finding the perfect living-room couch has begun to feel like the most important thing I’ve ever done.

I just thought right away that I wanted to work. ... This is a good job. It's been a good job. Work is the most effective drug there can possibly be. ... I'm on the periphery of a lot of despair, of course. ... You'd have to be stupid not to be. I have my moments when I'm not too thrilled about this whole deal. But at the same time, the songs have never come like this, so I'd have to feel more gratitude than anything else. I'm probably in the intensest creative period of my life.

When Milton's Satan stood in the pit of hell and raged at heaven, he was merely a trifle miffed compared to how I felt on that day. I felt totally alone, with the world receding away from me in every direction, and you could have used my anger to weld steel. Only my family and the fact I had fans in the medical profession, who were able to give me useful advice, got me through that moment.

When my father was in his terminal year, I discussed death with him. I recall very clearly his relief that the cancer that was taking him was at least allowing him "all his marbles". Dementia in its varied forms is not like cancer. Dad saw the cancer in his pancreas as an invader. But Alzheimer's is me, unwinding, losing trust in myself, a butt of my own jokes and on bad days capable of playing hunt the slipper by myself and losing. You can't battle it, you can't be a plucky "survivor". It steals you from yourself. And I'm 60; that's supposed to be the new 40.

It occurred to me that at one point it was like I had two diseases – one was Alzheimer's and the other was knowing I had Alzheimer's. There were times when I thought I'd have been much happier not knowing, just accepting that I'd lost brain cells and one day they'd probably grow back or whatever. It is better to know, though, and better for it to be known, because it has got people talking, which I rather think was what I had in mind.

I remember what George said and vowed that rather than let Alzheimer's take me, I would take it. I would live my life as ever to the full and die, before the disease mounted its last attack, in my own home, in a chair on the lawn, with a brandy in my hand to wash down whatever modern version of the "Brompton cocktail" some helpful medic could supply. And with Thomas Tallis on my iPod, I would shake hands with Death.

Did the Victorians fear death? As Death says in one of my own books, most men don't fear death, they fear those things – the knife, the shipwreck, the illness, the bomb – that proceed, by micro seconds if you're lucky and many years if you're not, the moment of death.