After years of observation and exploration I still have no answer for Guy. Yet people are always asking me this question, in every television or radio interview and in every piece I am commissioned to write, always with that embarrassed half-smile of the self-confessed rascal caught red-handed, always with that unmistakable twinkle of excitement and desire. Nobody escapes it. Everyone wants a share of the dream.

For nearly one hundred years now, Hollywood has astutely (perhaps maliciously) kept alive. I was the first to be fooled in my silly teenage years, when, carrying some vague recollections of Funny Face, I braved the Latin Quarter in a bulky black jersey as a prelude to falling in love with a Left Bank intellectual.

Audrey Hepburn would end up in the fashion houses of the Right Bank, and in the arms of Gary Cooper at the Ritz, in some other life. I, of course, didn't - and wouldn't for the life of me have deigned to: as a worldly Sorbonne student my Paris was clearly marked on the Left Bank, the only one conceivable. And I could think of no better place for a home than a tiny cosy garret huddled up against a Parisian sky. Hollywood avoided mentioning the shivering cold winters and stifling hot summers under those picturesque tin roofs, when delivering their papier-mâché sets for the tap dance of some charismatic American.

Nor was I forewarned that those cupboard-size chambres de bonne had no running water. And, of course, I was so uplifted by Rodolfo and Mimi's love duet that I overlooked the fact that it was in one of the leprous garrets of St-Germain-des-Prés that TB-ridden Mimi had given up her ghost. They had barely been upgraded when I was a student.

I have known others like me to have risen to the bait - the charming student who flew his unsuspecting girlfriend all the way from San Francisco in order to propose to her at the foot of the Sacre Coeur upon break of day; the nightly coachloads of lecherous old men who file into the lewd dives of Pigalle; the sedate retirees strolling hand-in-hand down memory lane; the millions of ordinary couples looking for some glitter for the celebration of a special occasion, the millions of vaguely hopeful singles, and the many infamous sinners in search of illicit adventures. Lovers and potential lovers the world over come to Paris with their store of anticipation and fantasies.

For decades I tried to figure out why Paris is shrouded in such mystique. Granted, walks at night along the Seine are enchanting, but that alone cannot explain why the very mention of Paris had always conjured up tales of romance, well before it was blessed with gas or electricity, well before its exquisitely lit street-corners were replicated the world over in black-and-white print.

After all, medieval Paris was a dark den of filth, reeking with nauseous stench, and the two sinister prison fortresses which jutted out of its skyline could hardly be conducive to romance. Not to mention the 32 rotting corpses dangling in the offing when the royal gallows were used to full capacity.

Yet the myth has been perpetuated for a good thousand years. Although occasionally there is the odd disappointed visitor, most cling to their image of Paris; if necessary they mishandle the truth for its sake, and understandably so - who cares to be reminded that everyday Paris can be blatantly unromantic, grumpy, tight-lipped and dour, filled with nerve-racking drivers, smeared with graffiti and explosive with social unrest, a far cry from the red-and-white checkered tablecloths and dainty white aprons that welcomed us to the Café de Paris in Medora, North Dakota, where Michel and I, the incarnation of the Parisian couple, were given the royal treatment by the sheriff.

Contrary to the myth, French men rank far behind their Anglo-Saxon counterparts as far as sexual activites go, at least so we are told by a recent poll. Even worse, it seems that Parisian men have lost the knack of seduction. A new school has opened in Paris on their behalf, l'Ecole de Séduction, which offers training to improve their skills. The London papers, which never miss an opportunity to bring the French down a peg or two, were quick to report this piece of news. Yet in the face of all those waiting to dethrone it, Paris remains the mystifying city of love.

I racked my brains, I dug into the past, I travelled into my own psyche, looking for an answer, but I came back empty-handed. There simply is no answer.

There lies the beauty of the enigma. Paris is poetry, Paris is mystery, Paris is beauty - an exasperating decoy which never quite delivers, all the more compelling for her imperfection, the archetypal reservoir of all our passions. We come to Paris as to a stage on which to enact an episode of our love life, but before we know it we are caught under her spell and find out, to our astonishment, that it is Paris herself that has got under our skin, the one love that has no rival and that even time will never erode.

It was when I realised that Paris was my one source of inspiration, the object, in turn, of both my celebration and desecration, that I understood that Paris herself is a tale of passion, full of turmoil and fury and dazzling charm, the very essence of romance. I stopped questioning, and awed by the mystery, I succumbed.