My 15-year-old daughter, Jasmine, is always telling me to turn down the music. Music isn’t a central part of growing up any more. For me it was everything: a window on to this other world.

I can’t believe I’m going to be 65 this year. I’m very fit and I’ve written six books in the last six years – I haven’t slowed down, I’ve picked up the pace. My generation is exploring a different way of getting old. Fitness has been important to me for a long time. I’ve been with the same personal trainer, Fred, for 13 years. I think everyone needs one – it’s not human nature to push yourself the way a trainer will push you. It keeps me lean, strong and calm, and helps me sleep.

About five years ago, I did my back in sparring. That was a horrible feeling, when you can’t defy age any more. But I did yoga for two years and it fixed my back. Yoga is a very intimidating thing for a man to do – far more so than boxing or a martial art – but I’d recommend it. You’ve got to keep your body strengthened, lengthened and toned.

When I became a father in my 20s, I had this illusion of immortality, but becoming a parent again in my 40s I realised that time is finite, you need to make a conscious effort to stick around to bring this child up. The first half of my 20s was screaming madness really. In your 40s you reach some kind of stability. Jasmine was a part of me wanting to get fit and be healthy.

I like a big glass of red wine to draw a line under the day, that I’ve put in a good shift, I’ve done good work, I’ve trained hard and I’ve fulfilled my duties to my family.

What I wish someone had told me when I was young is that your career will not be linear. There will be setbacks and disappointments and reverses at every step of the way. There will never be a time when you have ‘made it’. Success is largely determined by how we respond to disappointment.

Girl on Fire by Tony Parsons is published by Century at £12.99