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.

Before transitioning, I had a severe eating disorder. The doctor said, “Your body’s shutting down and if you don’t improve your mental and physical wellbeing, you’ll die.” Shortly after that, I started transitioning medically and my eating disorder resolved.

But in a flash there came across me a great project. The chine which the bridge spanned was full of young fir trees. Their slender tops reached to the level of the footway. 'Would it not' I asked myself 'be possible to leap on to one of them and slip down the pole-like stem, breaking off each tier of branches as one descended, until the fall was broken?' I looked at it. I computed it. I meditated. Meanwhile I climbed over the balustrade. My young pursuers stood wonder-struck at either end of the bridge. To plunge or not to plunge, that was the question! In a second I had plunged, throwing out my arms to embrace the summit of the fir tree. The argument was correct; the data were absolutely wrong. It was three days before I regained consciousness and more than three months before I crawled from my bed. The measured fall was 29 feet on to hard ground. But no doubt the branches helped.

What I expect to happen is that my body will fail, my mind will cease to function and that will be that. My genes will not live on, because I have had no children. I am comforted by Richard Dawkins’ theory of memes. Those are mental units: thoughts, ideas, gestures, notions, songs, beliefs, rhymes, ideals, teachings, sayings, phrases, clichés that move from mind to mind as genes move from body to body. After a lifetime of writing, teaching, broadcasting and telling too many jokes, I will leave behind more memes than many. They will all also eventually die, but so it goes.

Many readers have informed me that it is a tragic and dreary business to go into death without faith. I don’t feel that way. “Faith” is neutral. All depends on what is believed in. I have no desire to live forever. The concept frightens me. I am 69, have had cancer, will die sooner than most of those reading this. That is in the nature of things.

I believe that if, at the end, according to our abilities, we have done something to make others a little happier, and something to make ourselves a little happier, that is about the best we can do. To make others less happy is a crime. To make ourselves unhappy is where all crime starts. We must try to contribute joy to the world. That is true no matter what our problems, our health, our circumstances. We must try. I didn’t always know this and am happy I lived long enough to find it out.

I know it is coming, and I do not fear it, because I believe there is nothing on the other side of death to fear. I hope to be spared as much pain as possible on the approach path. I was perfectly content before I was born, and I think of death as the same state. I am grateful for the gifts of intelligence, love, wonder and laughter. You can’t say it wasn’t interesting. My lifetime’s memories are what I have brought home from the trip. I will require them for eternity no more than that little souvenir of the Eiffel Tower I brought home from Paris.

Thank God I found sobriety. I could sustain myself with my work, my reading, the movies, my friends. And walking, walking, walking. Of all the purposes of education, I think the most useful is this: It prepares you to keep yourself entertained. It gives you a better chance of an interesting job. ... I can't remember the last time I felt bored. I can't eat, drink or talk, and yet I have so many other resources to keep myself entertained. I think I must be a case study.

When I was a child the mailman came once a day. Now the mail arrives every moment. I used to believe it was preposterous that people could fall in love online. Now I see that all relationships are virtual, even those that take place in person. Whether we use our bodies or a keyboard, it all comes down to two minds crying out from their solitude.