It's more than 30 years since Syd Barrett vanished from view - and almost as long since the Syd Barrett Appreciation Society wound up its affairs, due to "lack of Syd". What would have happened if Barrett hadn't left - or been booted out of Pink Floyd? Presumably, he'd be just another rock dinosaur gamely going through his faltering paces to general scorn, or indifference.
Instead, he has become, as Tim Willis points out in his biography of Barrett, rock's Rimbaud, the "lost genius" who went away and never came back. "Both started new lives, leaving images of themselves which, unlike their contemporaries, will never age."