I learned three important lessons from watching 49 Up.

1. Think very carefully before growing a moustache.

2. Never be interviewed while lolling in a comfy armchair.

3. Try not to be born in the East End of London (as I was).

You could add a fourth: choose your parents wisely. An obstetrician friend of mine, and keen observer of parents, used to mutter, even though the kid had only just been born, “You might as well reserve that one a cell right now.” He approved of the Philip Larkin line, “they fuck you up, your Mum and Dad.” Which might explain why my obstetrician friend became an ophthalmologist in the end – you can fix eyes.

I am lucky enough to have had an alternative, imaginary Mum and Dad. A scion of a mega-wealthy philanthropic American family – let us call them the Bananas – once informed me that I was his long-lost son. My mother was the beautiful wife of the then Shah of Iran. I think this makes me the Prince of Persia. The downside is that whenever the Banana foundation donates another billion or so to some worthy cause, I am often moved to wonder, hey, where’s my share? The alleged streak of insanity running through the Bananas has never worried me in the slightest.

My real parents always took a benevolently laissez-faire attitude towards any and all of my bright ideas. “You want to become a rock star/movie director/Mr Big in some global criminal conspiracy? That’s very nice, dear.” True, my mother did momentarily knock me back with her remark that one day I might write a book like that nice Jeffrey Archer. Other than that I can’t really complain.

My evil twin brother was born a mere 10 minutes before I was, and if astrology is right, then a lot of planets must have moved house by the time I arrived. He became an astrophysicist while I ended up … here. Which is probably why I tend towards a quantum sense of chaos and random particles colliding in life with unpredictable results. As they say in Terminator, the future is not set. I always like to think that whenever I blow it badly on this world, there is a fine parallel world out there on which my more successful alter ego did not blow it and lives happily ever after.

But even without parallel universes, if evolutionary theory is right, then it is impossible for us to blame our parents for everything. The three rules of evolution are mutation, mutation, mutation. Of course there are those cases where a dentist father begets a dentist son (or similar), but this is the exception that proves the rule. Certainly by the age of 49 you pretty much have to own up and take responsibility.

I have always admired the judge in the case of an American villain on trial for some particularly blatant murder, with his DNA smeared all over the murder weapon, whose defence was, “My brain made me do it!” The judge nodded sympathetically. “I fully agree, your brain did make you do it. I am therefore sentencing your brain to 25 years. But unless you want us to take your brain out and stick it in a vat, you’ll have to be locked up with it.”

I found myself identifying with one of the more eccentric 49ers who spoke movingly of a moment of epiphany. A big beautiful butterfly alighted on a flower near him and our man thought to himself: I need to be more like this butterfly. I may not have that long to live and I am doomed, like him, to return to dust soon enough, but so long as I am around I can try to be beautiful. Or at least just be.