The life of Georges Simenon began with a lie. He was born, during a rainstorm in Liège, 10 minutes into Friday February 13, 1903, but his superstitious mother insisted the birth was registered for the more auspicious Thursday. So, for 86 years until his death in Switzerland, he lit candles annually to a fiction and, in three months' time, his centenary will be celebrated one day early.
But the possession of a duplicitous birth certificate is appropriate because the man who became one of the essential writers of mysteries (rivalled in popularity only by Agatha Christie, Arthur Conan Doyle and Edgar Allan Poe) was fundamentally a mysterious writer.
The first question Simenon raises is the explanation for his literary and sexual excess. What drove an imagination so prolific that he was able to write a novel in 11 days? (Starting a new book, he would mark off on a calendar eight days for composition and three for correction.) In the 1930s, when a French publisher took out advertisements announcing that a writer called Kessel was publishing "his first novel for three years", the creator of Maigret responded with cheeky flyers boasting "the first Simenon for eight days".
A remarkably prolific novelist, Simenon was also an astonishingly gushing lover. In old age, he claimed to have had sex with 10,000 women and, while all claims of erotic prowess are subject to a certain rounding-up, it's clear he used prostitutes at the rate Parisians get through Gitanes.
Beyond these enigmas involving his imagination and his penis, there are other mysteries to be considered by any writer investigating him, as I have for a Radio 4 play marking his centenary. Part of the reason this Belgian, whose most famous character was French, spent the last 40 years of his life in America and Switzerland was the accusation that he had collaborated with the Vichy regime during the second world war. There is also the question of why his daughter killed herself.
The main biographers - Pierre Assouline (1997), Patrick Marnham (1992), Stanley Eskins (1987) and Fenton Bresler (1983) - frequently disagree on details of the author's life but they are more often contradicted by the more than 20 volumes of autobiography which Simenon himself published. That torrent of autobiography is not even internally consistent. For example, he gives several different accounts of the genesis of his signature character, Superintendent Maigret.
A man who had published at least 400 novels under his own name and a variety of others would frequently lament to interviewers that he had always been incapable of making anything up. Certainly, he transferred a number of people, names and places wholesale from his research to the novels and, in consequence, suffered a number of libel suits. More gravely, when his 25-year-old daughter, Marie-Jo, decided to shoot herself in 1978, she was able to get the name and address of a reputable Parisian gunsmith from one of the Maigret stories.
Reluctant to admit fiction to his novels, Simenon was unusually inventive in real life. It is still, for instance, widely claimed in literary histories that the young Simenon once wrote a novel in public in 24 hours, while sitting in a glass cage in Paris, accepting character and plot suggestions from a gawping audience. The author did not discourage this legend and it became a perfect metaphor for both his exhibitionism and his profligacy. However, his biographers have proved that Simenon never in fact became a literary sea-lion in this way. He signed a contract for the transparent composition but cancelled the happening after being warned by friends that it would wreck his artistic reputation. As with his birth certificate, the misunderstanding seems appropriate.
Apart from the personal memories that went through more drafts than a Hollywood screenplay, he had what might be taken as a novelist's habit of renaming key players in his life, so that his first wife, Regine, was rechristened "Tigy", while her maid Henriette, with whom the libidinous Simenon had an inevitable affair, was asked to answer to "Boule". The second wife, Denise, seems to have held on to what she got at the font although, in an intriguing psychological sideswipe, she began to spell herself Denyse after their marriage ended.
During the 1950s, when Simenon was living in magnificence by Lake Geneva, one of his neighbours was Carl Jung. The crime writer was keen for a meeting and an appointment was made but was cancelled by the psychologist's death. Yet a session with Sigmund Freud would probably have been more appropriate. The more you learn about the author, the more you conclude that his childhood damaged him profoundly.
In the classic no-win of parenting, his father loved Georges too much, his mother too little. His father, Desire, died at only 44 from a heart ailment he had concealed from his wife, who had come to the alternative diagnosis of laziness. Shortly before dying, Simenon Sr gave his son a pocket-watch, which he later used as payment in a brothel. These events gave Georges three obsessions - with early death, timepieces and his mother's cruelty - which became driving forces in his writing.
Henriette - the target of a bitter, late non-fiction book, Letter To My Mother - distanced herself from Simenon not only by her alleged part in hounding his sainted father to an early grave. Most shockingly, when Georges's brother was killed, she complained to her surviving son: "Why did it have to be him? Why couldn't it have been you?"
There's a popular psychological theory that men who are rejected by their mothers often become obsessive copulators, seeking vaginal acceptance, the compensating embrace. There are about 10,000 reasons to believe that Simenon fits that groove but there's also a more exotic and enjoyable theory that, in his many forays into bedrooms and brothels, he was following his nose.
As first a child and then a writer, he had an exceptional sense of smell, which was inconvenient for the many secret drinkers in his family. Because sexual attraction is, underneath what we call love and romance, a positive response to someone else's odour, there's some medical suggestion that those with unusually responsive nostrils may also be more sexually aware.
The wound of being unloved by his mother may explain as well why Simenon, in at least one case, became too close a father. The daughter to whom he gave his own name - Marie-Georges, later shortened to Marie-Jo - became so devoted to him that she once fainted when he drove past her without stopping and, as a young child, insisted he buy her her a gold wedding band, which she had stretched as she grew older. Before shooting herself with the gun to which Simenon's fiction had directed her, she is reported to have spoken of her father's "crushing genius".
Even so, he was a tragically unintended accessory to his daughter's death. The possibility of more direct culpability comes with his behaviour during the occupation of France. Simenon worked for the German film company Continental, whose owner kept a bust of Hitler on his desk - this period is also covered in the latest Bertrand Tavernier film, Laissez-Passer - and lived in a castle in the Vendée where Nazis had been billeted. To receive his royalties, he signed a declaration that he was Aryan, although he crossed out the lying claim that he was French rather than Belgian.
Simenon later claimed protection under a popular post-war formula in France - that he worked "under" the Nazis rather than for them - and the liberation government, despite investigation, found insufficient evidence to deport or execute him. Yet guilt and fear about his war-time record made him a voluntary exile from France. He had written anti-semitic articles as a young reporter in Belgium but my conclusion was that he was more pro-Simenon than pro-Nazi. With the egotism and political naivety of many artists, he simply could not accept that something as trivial as a world war could interrupt his career.
He was an unstoppable novelist. In the mature phase, which followed apprentice texts under numerous noms de plume - including Gom Gut, Christian Brulls and Jean du Perry - Simenon published three kinds of novels. Those he took most seriously he defined as "hard" books, which sub-divided again between crime stories (usually psychological puzzles) and more general domestic and sexual narratives. These were the works that he hoped would bring him the Nobel. On the other side of the divide were the dozens of Maigrets that he would have regarded, to borrow Graham Greene's distinction, as "entertainments" rather than serious novels. To his distress, his reputation came to rest on these: first for readers and then viewers. After they began to be widely translated in the 1940s, there were two British television series that became international hits, with Rupert Davies as the detective in the 1960s and then Michael Gambon in the 1980s.
Patrick Marnham called his Simenon biography The Man Who Wasn't Maigre, acknowledging the irritation both authors felt with lazy identification. Yet the creations of most novelists contain at least some shards of mirrored glass, even if of the distorting kind.
In one crucial way, the Parisian detective is very different from Simenon: he is uxorious, if sometimes a little grumpily so. There are, though, strong mental connections between the two men. Maigret is a bit of a plodder, under-estimated by his peers but then surprising them with his results, a possible reflection of the inferiorities Simenon felt as a son pushed away by his mother and then a Belgian living in France. Maigret's age when he first appeared in the fiction - in the late 1920s - is also significant. Jules Maigret was born aged 45, the birthday Simenon's father had failed to reach.
Simenon's hero differs from iconic fictional detectives such as Sherlock Holmes and Poirot in that he insists he "has no method" and rarely relies on brilliant deduction or theatrical interrogation. His trick is to think his way into the head of either victim or suspect. The English crime writer and critic HRF Keating has suggested that, in giving his creation such investigative procedures, Simenon was the first author in the genre to present the detective as a writer-surrogate. Like a novelist, Keating argues, Maigret begins each investigation by entering a new place or profession about which he has to learn - a version of authorial research - before coming to an intuitive understanding of the characters who inhabit it. It's a measure of Simenon's reputation in the genre that Keating, in his 1987 survey of the 100 best crime and mystery books, awarded three places to Simenon with two novels from the detective series - My Friend Maigret (1949) and Maigret In Court (1960) - and one "hard" book: The Stain On The Snow (1948), the story of a young man who becomes a killer and rapist during the Nazi occupation of France.
Keating's book is arranged chronologically but he says that, were the titles ranked by merit, Simenon would take first place, probably for My Friend Maigret . The late Julian Symons, another crime sage, also selected that title as Simenon's best.
Shortly after finishing the play, I met someone whose parents had once had a professional connection with Simenon. They were invited to stay at his Swiss mansion and, about to go to sleep in one of the master bedrooms, flicked the switch they assumed to control the lights. The room remained illuminated but they suddenly heard conversation from another room. Trying another switch, they overheard private chat from elsewhere. They concluded that the author had the place wired.
This might be regarded as the action of a pervert but can also be interpreted as evidence of the novelist's desperation to know and tell the stories of everyone. And, with Georges Simenon, the dividing line between sleazeball and creative artist is often hard to draw. Though he never wrote a novel in a glass cage, he built around himself, in both his fiction and his memoirs, a tower that seems to consist of windows until you gaze into them and find they are either mirrored or opaque.
It became a critical and journalistic commonplace that Simenon secretly longed to be a detective and, in 1934, he humiliated himself by announcing that he would solve the Stavisky case, a financial scandal that brought down the French government. He failed even to find a new lead and, like many crime writers, was forced to accept that it's easier to work backwards from your own facts than forward from existing ones.
More plausible is to see Simenon as a criminal manqué. Certainly some aspects of his biography - principally the brutal rejection by the mother - are familiar from profiles of murderers and we should perhaps be thankful that he was a balanced enough man to respond to his psychological problems by picking up a pen rather than a gun.
He also clearly enjoyed the idea that his life and writings were leaving a trail of clues, some true but many false, of which others would have to make sense. Both literary biographers and murder detectives will tell you that it's generally a good idea to talk to anyone with whom the subject had a sexual relationship. Among his many other precautions against being understood, Georges Simenon ensured that such an approach would be impractical in his case.
· The Man Who Had 10,000 Women by Mark Lawson, starring Derek Jacobi and Joss Ackland, will be broadcast on Radio 4 at 2.15pm on Tuesday. A series of Maigret adaptations starts on Radio 4 on December 3. Six of Georges Simenon's Inspector Maigret novels will be reissued as Penguin Modern Classics next year, along with a new paperback edition of The Man Who Wasn't Maigret , by Patrick Marnham.