I don’t want to bum you out or anything, but — Here it comes. O.K., I’m sitting down.

When you see your life laid out in this way, do you start to think about your own mortality? Well, of course I do. Part of the experience of being my age, and particularly in my corner of my field, is that — oh, gosh, I could click off the names, but all sorts of people I’ve had a drink with, and then all the people in my group, with the exception of one, are all gone. So, obviously, I begin thinking about myself.

What, exactly, do you think? Well, O.K., I’m alive. Great! So what’s good about that? That’s Question 1. Then: What is a reasonable amount of time that I can look forward to? You want to be sensible. For instance, I had a sports car, and a few years ago I realized it’s not cool for a guy over 65 with 20/40 vision to be getting ticked off when somebody’s driving less than 100 miles an hour in front of it. And so I traded it in for a dad car. A big one, though. I don’t want to become totally sensible.

Was the loss of David Bowie an especially difficult one? At first I didn’t process it. I thought, They must be talking about someone else. But then I got it. I went to a rehearsal, and when we ran through “China Girl,” there’s a guitar theme at the end of that, that was written by that person, with a guitar, with his hands. I can see the person, I can see the hands, I can see the guitar. And he’s not on this plane anymore. That came up several times that day.

“Lust for Life,” perhaps the most famous collaboration between you and Bowie, will appear in the coming “Trainspotting” sequel. What was that original collaboration like? He wrote the chord progression and beat on ukulele. The inspiration had come from the American Forces Network television station in Berlin that had a call signal that went “beep beep beep — beep beep beep beep beep — beep beep beep.” We were sitting on the floor, and I taped it on a little Philips cassette recorder that I used to carry around. David told me to call it “Lust for Life.” I tried to sing a character song and to conflate myself with the William Burroughs character Johnny Yen, who is a green Venusian love boy. Sounds like fun, right? Who wouldn’t want to be a green Venusian love boy?