Loitering in one of the scores of cafés and bars that occupy every other shop front on Rue des Abbesses, I’m suddenly very aware of the lumpish and melancholic pall of age. I’m invisible. As the silver haired gent by the window immersed in his book and distractedly forking his food, or the blue haired lady in the corner sipping white wine and absently stroking a lap dog are invisible.

A gorgeous young woman and her affable sidekick perform a swirling pas de deux, moving fluidly between the tables the bar and the kitchen, their musical bon soirs interspersed with the scrape and judder of furniture as they constantly remake the space. Somehow the flow of food, the clatter of bottle caps and clink of carafes on the marble tabletops continue uninterrupted. What they lack in obsequious ceremony, this pair more than make up with their amiable proficiency and the unselfconscious loveliness of careless youth.

On the heated patio outside other beautiful young couples sip their drinks, smoke, nibble at food and each other, some of them momentarily amused by the wisps of snow that are beginning to fall.

I’ve come to Paris to meet a friend I haven’t seen in 40 years, and as a distraction from morbid thoughts.

There must be few more delightfully distracting places than this confusion of cobbled streets and alleys and squares in the immense shadow of the Basilica of Sacré-Coeur. A chaotic admixture of sacred and profane, devotional and decadent, physical and cerebral; treats for the soul, the imagination and the viscera.

The wet black cobbles of the winding streets glisten under leftover Christmas lights slung between buildings. Eventually I find myself in Place Susanne Buisson where the lights in the trees twinkle like cheap jewellery. There are bars and bistros crowded all round the square, their heated patios filled with sippers and smokers and nibblers. I am enjoying the comfort of crowds but feel no need for company.

I’m now invisibly seated beside handsome Russian girls who smoke Marlboros avidly and flip between Russian, French and English as easily as characters in a Nabokov novel. The Russian girls’ Russian girlfriends arrive, sparking a distinctly un-Nabokovian frenzy of squeals and shrieks and kisses all round.

We had much to talk about my friend and I. A lot of life gets crammed into forty years what with lovers and friends and families, moves and migrations, careers and unfulfilled ambition, sickness and death, lurid addictions and addled fancies, passing fads and lifelong passions, tragic flaws and comic foibles (which by now are hardening inexorably into cranky eccentricity). For that one evening, time is compressed into a two-dimensional panorama of the anarchic, chaotic comedy of being.

The Russian girls tra-la tri-lingually beside me, the bustling waiters duly ignore me, a newly arrived trio move tables around, one of them nodding an almost imperceptible acknowledgement of my existence as he manoeuvres a chair between me and the table. I am as completely and utterly inconsequential to everything and everyone around me as if I was seated in a theatre, a part of the event but individually of no importance whatever.

For forty years contending has been the thing and now I’m no longer in contention. Contending for lovers, contending for the money, contending for attention, approval, admiration, applause. This realisation, too banal and predictable to be dignified as insight, is profound only in the strength of my conviction that I’ve crossed over my own fourth wall from actor to observer.

It feels like the first truly new sensation in a very long time.