I hit a bit of lumpy tarmac driving my motorbike over the Pyrenees in the early 1980s. There was no safety barrier and I found myself riding along the edge of a precipice on half the width of the tyres for 100 yards.

Abseiling down a cliff for Doc Martin in a suit, carrying a medical bag.

Today is a pretty important day. It was August 15th, 2007, when I was told I likely had "three to six months of good health left." Today is six months from that day. Just to prove I'm still alive, here I am, holding today's New York Times! I rode my bike today; the cumulative effects of the chemotherapy are hurting my stamina some, but I bet I can still run a quarter mile faster than most Americans. The doctors weren't wrong; they always said that if the palliative chemo worked, I'd buy more time, but that it was a long shot. And the doctors have done a brilliant job of tweaking my regimen to help my odds. How much longer this will work is hard to know, but I'm going to keep having fun every day I have left, no matter how many or how few of them I get.

Being charged by a white rhino on a walking safari. It came running towards us and I froze, which is the right thing to do. If it had hit us, it would have been goodnight.

And of course, I wonder why I was not more vigilant about checking my skin, because if I had been, I would have picked up that first melanoma before it turned bad, and saved myself a lot of heartache. When I was first diagnosed, I was angry with myself for being too lazy and stupid to bother with anything but the occasional quick examination. But then I decided that kind of thinking was a waste of my time, because we start dying the moment we are born. I know that now. The knowledge has changed from a first illuminating but soon forgotten premonition into an undeniable lived reality.

He’s always been the family cook. He’s been feeding me since the day we met. Everything I know about Japanese food I know because of him. So now that’s another pleasure gone, perhaps the greatest. I don’t know how long it takes to die of starvation, or whether it hurts, but I dread it, just as I dread my sons watching me go like that. Because that is what they will remember, their mother reduced to a bag of bones. What it will do to Shin I can’t bear to contemplate.

So many times I’ve wondered what might have happened to me if I had lost my legs, or even just my right one, where my first melanoma appeared two or three years later. If I’d just been a second slower stepping away from the car, I might not be dying now. I’d be legless, of course, but still in good health. Of these fateful forks in the road are our lives made up. We are all just a millimetre away from death, all of the time, if only we knew it.

I move from my bed in my bedroom, to my sofa here in the living room, and basically I stay here and I'm fed delectables all day and that's about it.

As far as I can tell, I’ll either succumb to some opportunistic infection, for which I’ve refused antibiotics in advance, or, having similarly declined forced feeding, I’ll starve to death. ... I don’t know how long it takes to die of starvation, or whether it hurts, but I dread it, just as I dread my sons watching me go like that. Because that is what they will remember, their mother reduced to a bag of bones.