If you’d asked me at 20 where I expected to be 30 years later, I’d probably have said deep-sea diving on Europa; my friends placed bets on Hendon Crematorium. Instead of either of these eventualities, however, I am here: a mile down the road from the old Archway squat, older, wider, with two books on the shelf, two kids on the verge of adolescence, one remaining friend I barely see, and piles.

When my daughter was born I’d just turned 37, and made an uncomfortable calculation: by the time she reached 13, I’d be 50. It seemed impossibly distant; but then parenthood intervened. My son arrived two years later; at 40 I had two novels accepted, an agent, two kids: the world was my oyster.

So where are we now? Well, back in N19, where most of the past 32 years have been spent, in a large, crumbling housing association place, a wife who works full time, a daughter now in year eight (or, as we pre-millennials call it, second year); a precocious 10-year-old about to enter his final year in primary school; and two more books on the shelf, which I self-published not because, you know, no one wanted them, but because this way I’d retain full artistic control and that. You’re not buying it, are you? Sadly, you're not alone, as the Amazon chart daily reminds me.

When my wife announced her intention to return to work full time, I was overjoyed: now at last I’d have time to write my Great British Novel, catch up on Shakespeare and Proust, visit the occasional gallery and hang out at the British Library. Sadly, it hasn’t quite worked out that way.

Although Daughter, 13, leaves the house at eight each morning to walk the half-mile to school, I still have to walk Son, 10, myself; this is a high point of the day (“Daddy, I’ve been reading about existentialism lately and come to the conclusion there's no point doing any homework”), but by the time I’ve popped into Sainsbury’s, loaded the coffee machine and washing machine, unloaded the dishwasher, re-washed all the dishes, and sat on the loo sobbing, it’s gone 10.

The Duchess of Cambridge meets parents from Prince George's new school

Theoretically, I still have five hours before walking back up the hill, avoiding eye contact with all the other parents with whom I’ve passed the time of day for almost 10 years, collecting Son, 10 and coming home to make dinner (or, to be more accurate, letting Wife make it). But by the time I’ve caught up on essential and indeed non-essential emails, checked the hits on my web page (zero), sales of my four books (zero), hung out the washing (I’m probably the best person in N19 at arranging wet clothes on the clothes horse – if only the New York Times handed out reviews for clothes-hanging...), checked the news to see if Isis have done anything exciting today and called Nan, 95, to make sure she’s still alive, it’s almost lunch.

Hemingway used to carry a crate of spirits wherever he went, so that when asked to dine with some Count in his castle or war-lord in his tent, he’d always be able to choose his own tipple. I have a similar system with Cup-a-Soup. I carry a box of assorted flavours at all times, and if I’m feeling dangerous, close my eyes and extract one at random (to be honest, though, when it’s Stilton and broccoli I do tend to put it back and select tomato).

Post-lunch, as I stare aghast at what I haven’t written yet, it dawns on me that the house is a tip. The living room is a mass of dirty plates, scraps of paper, print-outs, odd socks, vacuous “books” by 11-year-old YouTubers who sell more publications per pica-second than I’ve sold in 50 years, and those little cellophane straw-holders attached to juice cartons I sometimes think will be my single most abiding memory of parenthood.

Baby sees his father for the first time with new glasses

So I stack the plates, push the hoover round, stick on another load of washing and a load of words on my laptop screen (“all work and no play makes Mark a dull boy. All work—”), so when Wife returns it looks like I’ve been doing something all day rather than just procrastinating. It’s called Kidology. It might not seem much of a life, but at least I’m still here. I suppose.

Half a century not out. At 100 you get a telegram from the Queen, but after 50, you get nothing. I’d have settled for a text from Vernon Kay.