Cook said he “ran out of ambition at 24″ – in 1961, when he had a revue in the West End as a Cambridge undergraduate; certainly, by 1981 his comedy had reached an impasse. He tried Hollywood, appearing in a bad pirate film called Yellowbeard and a feeble “feminist” version of Superman called Supergirl, where, he said, he “sat around on the set for 16 weeks”.”Sat around on the set” – it’s a telling admission; Cook had, finally, stopped trying. But when people asked, ‘What are you going to do now?’, I really didn’t know – I still don’t really.”He cast around for a role. In 1981, he agreed to take a bit part in an American sitcom called The Two Of Us, flew over to New York, played a supercilious butler for 20 episodes, and found America “ridiculous” His show was axed by CBS. “It produced a gap in my life which is probably still there today,” he said in 1991 “I wasn’t envious because I didn’t want that life.

Of course, he mocked Moore’s new life in “a ghastly place full of factories, freaks and health fascists”, but behind his quips – “It’s OK if you’re an orange” – there was sadness, and fear about the loss of his favourite collaborator. Most of the viewing public had no idea that it was Cook and Moore who had inspired Python’s mix of the crude and the arcane; worse yet, Moore had left Cook for Hollywood in 1975, and Derek and Clive was more of a one-off virtuoso reunion than a new beginning Cook saw their split as “a divorce”. Above all, Cook had influence: from the Monty Python team to every student revue in the country, comedians followed up the innovations of Not Only But Also.But the truth was that Cook’s career had stalled. Did Cook just lose his comic demon, his days listless after breakfasts of lager and vodka, or did he consciously decide against “achieving one’s potential”? And if he did reject success, what took its place?COOK’S LAST YEARS started around 1980. He had, it seemed, ended the Seventies as he had begun them, in famous, hilarious partnership with Dudley Moore. The Derek and Clive personae they adopted in 1979 were foul- mouthed, more aggressive versions – to suit more aggressive times – of the droll-but-puzzled proles they had played to such acclaim as Pete and Dud in 1969.

Cook had had his problems during the decade – a disastrous chat show axed in 1971; a Daily Mail column that stalled in 1977; a failing second marriage to actress Judy Huxtable – but he was still a brilliant improvisational comic, capable of unfurling great strings of compelling nonsense about whales making records or great barrages of mocking insights into the Jeremy Thorpe trial, barely moving his long, imperious head while all collapsed laughing around him. But even these small pleasures have fed the melancholy myth: Cook’s widow, Lin Chong, is reported to have found the relaxed work ethic of the Private Eye staff not to her liking; and the thousands of hours of living-room tapes recorded by George Weiss flesh out the image of Cook bloating in Hampstead like Elvis at Graceland.Still, the question of his dereliction remains: how had the young blade of Beyond The Fringe, deadpan and slicked-back as a Kray Twin, ended up – to quote some of the unkinder descriptions written in the years leading up to his death – “shrouded in blubber”, “eyes swimming in pink gin”? Of the Beyond the Fringe team, Dudley Moore went to Hollywood, Jonathan Miller to direct opera, and Alan Bennett to every bookshop in the country; only Cook, apparently, went to seed. But, at the same time, the Pebble Mill interviewer’s question acquired a new resonance: how had the genius who had dominated British comedy since the early Sixties ended up as he did, not pushing back the frontiers of comedy still further but baggily haunting neighbours and chat shows and tabloids like another Oliver Reed?Friends and admirers skated round the question, cramming Cook’s last 20 years into a sentence or two under the euphemism “disappointing”. Alan Bennett spoke politely of Cook’s “later years when some of his talent for exuberant invention deserted him”. And Stephen Fry, who had grown close to Cook, felt obliged to go on to The Late Show and tell viewers not to feel sorry for Cook: “He had his friends, his Private Eye [Cook was the majority shareholder], his television to watch, his newspapers to read, and fun little jobs to do every now and again…” Perhaps. His potential was never to be achieved, but any doubts about the depth or endurance of his creative reputation were quickly dispelled by a flood of tributes: from the year’s fondest obituaries and a paean of a leader in the Times in January to a second wave of eulogies from friends and colleagues like John Cleese and Alan Bennett at a memorial service in Hampstead in May. “What could be worse than to achieve one’s potential so early in life?” Within six weeks, Cook was dead, aged 57, killed by a gastrointestinal haemorrhage that was probably brought on by years and years of heavy drinking.