All sorts of things can keep one awake. But as you get older - this is what the stroke thing really brought home to me - this thing that I never paid attention to: my brain. I've always been conscious that, of course, after a night of getting stoned, my head would feel foggy; if I got drunk the night before I'd be hungover. But that was the extent of my concern about my brain. And then with the stroke thing, it made me realize, "God! That's my main source of income." So it relates actually to your other question about growing old.

The perfect life, the perfect lie, I realised after Christmas, is one which prevents you from doing that which you would ideally have done (painted, say, or written unpublishable poetry) but which, in fact, you have no wish to do. People need to feel that they have been thwarted by circumstances from pursuing the life which, had they led it, they would not have wanted; whereas the life they really want is precisely a compound of all those thwarting circumstances.

There's always something impressive when people are giving themselves to their job absolutely. The military thing - I was conscious that their routine, their way of living is so opposite to mine. In some ways their life seemed intolerable to me. But, mine would be to them, too, because this strangely laissez-faire life of mine actually comes with its obligations as well.

[William] Eggleston's photographs look like they were taken by a Martian who lost the ticket for his flight home and ended up working at a gun shop in a small town near Memphis. On the weekend he searches for the ticket - it must be somewhere - with a haphazard thoroughness that confounds established methods of investigation.

Never ride a bike with the brakes on. If something is proving too difficult, give up and do something else. Try to live without resort to per­severance.

In foreign countries, when people see what Donald Trump is saying on Twitter since the election and seeing what he's saying in these calls with foreign leaders, they take everything very seriously and they take everything very literally.

I think, about the distinction between fiction and nonfiction. Fiction is not really about anything: it is what it is. But nonfiction - and you see this particularly with something like the BBC Samuel Johnson Prize for Non-Fiction - nonfiction we define in relation to what it's about. So, Stalingrad by Antony Beevor. It's "about" Stalingrad. Or, here's a book by Claire Tomalin: it's "about" Charles Dickens.