I can still remember the first time I saw Robin Williams on screen. It was as Mork, but it was before he had his own series, and he was busy befuddling and bemusing The Fonz with a walk-on role in Happy Days. It didn't take long for TV bosses to spot the comedic gold to be mined, and soon the loveable alien in blue and orange stripes had his own show, falling in love with Mindy and calling Ork when there was strange business to report from Earth.
Immediately I, along with all his legions of fans in the many countries where the show was broadcast, identified with this sweet, confused, otherworldly character. His zaniness was paramount, his comedy just one of his instruments for dealing with the confusion of an overwhelming planet.
I didn't realise I was watching an already established legend of the stand-up circuit. It was only when the newly A-list Robin Williams started appearing on British chat shows that I realised that the kinetic energy belonged to the actor, not the script. His machine-gun riffing, his ability to put on a thousand voices and tell circular jokes poking fun at the human condition were all proof of comedic genius, seemingly channelled from another source for which he was merely a willing conduit. No wonder performing greats like Bob Hope were reluctant to follow him on stage. Billy Crystal once said it was like trying to top the Civil War.
On the big screen, Robin Williams' cleverest directors were the ones who realised they had a whitewater river of expression at their disposal, and they should channel it rather than try to dam or control it, that they were better off simply providing the best environment for their leading man to let rip.
This unique gift proved a surprisingly adaptable resource, hence the success of films as diverse as Good Morning Vietnam and Mrs Doubtfire, and his unique contribution as the voice of Genie in Disney's Aladdin.
Occasionally, Robin Williams' palpable warmth bubbled over. He, or his directors got the balance wrong, too much sugar was added and 'sentimental' became 'saccharine' as in the box-ticking Patch Adams. When he got it right, the wit perfectly countered the warmth in films as watchable today as when they first appeared. I'm thinking of Dead Poets Society and Good Will Hunting, where the sensitive Gus Van Sant steered him to his Oscar.
Later, the most surprising revelation came with his villainous roles. In Insomnia, he held his own against Al Pacino, no less, and One Hour Photo was virtually a one-man virtuoso display of what he had inside him when all the baubles of bubbling humour were packed away, he had the opportunity to down tools, confound audience expectation and perform without the safety blanket of the gags.
But, for me, as for so many others, Robin Williams' shining moment came with his moving, rousing, inspiring performance in Dead Poets Society. Everything he was - witty, sincere, sad, conscious of love, loss and life, and, above all, generous - came together in this glorious piece.
It has always pleased me no end to know that Robin Williams had been the best friend of Christopher Reeve since their time together as acting students, and that much of his tireless charity work had been for the benefit of that equally great man's foundation. It pains me to know that both these unique characters are now gone. And, just as Christopher Reeve's night-time flights as Superman have ever since his accident proved bittersweet viewing, so too will the sight of Robin Williams' evergreen young men standing on their desks to chant,
"O Captain! my Captain! our fearful trip is done,
The ship has weather'd every rack, the prize we sought is won..."
This was his reward for telling them to seize the day, and make their lives extraordinary. As Robin Williams certainly did.