I’m 57 and as the great philosopher Leonard Cohen once said: ‘I ache in the places where I used to play.’ I’m very aware that my hearing isn’t all that it used to be, my knees ache most of the time and my lower back gives me problems. It’s all the stuff I used to take for granted.

I’ve had a few friends in the past year or two who’ve died in their 50s and 60s; so, I wonder, should you rein all the good living back to maybe live longer, or remember you’re only on the planet once and enjoy yourself? It has to be a balance, I think, being able to say: ‘Oh hell, we’ll have another bottle of wine’, and not be on a diet that you hate.

I recently went to a resort that was very focused on wellbeing. I was getting a massage every day but all the stuff to do with tai chi, yoga and meditation, I just thought, ‘No thanks.’ I’m a working-class Scot at heart and very resistant to the new age stuff; the far reaches of saying we can all live for ever if we just use a spiraliser and drink cucumber water. I don’t think so. That has me reaching for the beer.

What you’re doing is what you were doing as a kid; playing with your imaginary friend

My character Rebus is much more conscious of his own mortality so I guess that reflects on me as I grow older. He lives more or less in real time, so the guy I wrote about 30 years ago now has aches and pains. I’ve given him some health issues in my last book, he’s got chronic obstructive pulmonary disease; it can be controlled, but you don’t get better from that.

I think writing is good for your brain - you have to work hard to connect characters, situations and incidents, and resolve it all by the end. That’s why writers tend not to retire. What you’re doing is what you were doing as a kid; playing with your imaginary friend, and that’s what keeps me feeling young.

Rather Be the Devil by Ian Rankin (Orion), £6.79 from guardianbookshop.com