Trying to decipher the art of David Lynch, as if he were in the business of producing particularly fiendish crossword puzzles, is not going to get us far.
His work is all about surrendering to the uncanny depths of the imagination. But learning about the man behind it all is another matter. That is eminently possible - but is it, for his fans, desirable?
In one of Lynch's favourite films, The Wizard of Oz, the curtain is swished back to discover a puny sham wizard pulling a bunch of levers. What if the maker of Twin Peaks, Blue Velvet and Mulholland Drive turns out to be something like that, too?
This intriguing half-autobiography seems designed to demonstrate that this is not the case, that Lynch really is of the same substance as his films. Starting with his ordinary picket-fence childhood, the book is written in alternate sections, with the film-maker's entire life story told in third-person chunks by the journalist Kristine McKenna, after which the baton passes to Lynch himself, to see if he remembers things in quite the same way.
This being Lynch, the quality of his recall is skewed and sometimes hilariously selective. Famously unwilling to anatomise the "meaning" of his films, he equally wafts away whole passages of his life story as if they were dreams he once had, the outline hazy and diaphanous.
Growing up in Boise, Idaho, in the Fifties, he barely has a sense, for instance, of what films he might have seen as a child. But one extraordinary memory jumps off the page: of playing with his brother one night on the street, when a naked woman, evidently traumatised, came out of the darkness. "It seemed to me that her skin was the colour of milk," Lynch writes, "and she had a bloodied mouth."
There's no doubt what a formative effect this apparition had on a young boy's view of the world. Long after, it would surely inspire the astonishing scene in Blue Velvet (1986) when Isabella Rossellini is found naked and battered on the detective's front lawn.
The one is an (un)dress rehearsal for the other: Lynch had had 30 years to ask himself questions about a briefly glimpsed stranger who said nothing. What might her story have been? This is so often the way he seems to work - leaping on chance encounters, or overheard fragments, to forge a vision that is hallucinatory, seemingly hard to explain, but naggingly recognisable as part of our world.
Another example: "Dick Laurent is dead." This twice-heard statement bookends Lost Highway (1997), Lynch's neo-noir, giving the film an eerie structure as a self-fulfilling prophecy, a twisted loop like a Möbius strip. That he got the idea for it from an unknown person buzzing his intercom at home and saying those exact words - perhaps a neighbour, passing news to the wrong house, before disappearing - is so very Lynch, and nuggets like this are gold for his fans.
They prove that the reasoning behind his choices is a matter of a particular feeling that he has had, and that he wants to pass along. Stories abound in this book of him casting roles by simply staring askance at an assistant one day, or spotting an old lady on the street who seemed just right.
Lynch's odd, spontaneous impulses make him hard to pin down as an artist, and just as slippery as a husband. He has had four marriages now, with a child from each. He eloped with Rossellini after casting her, and divorced his second wife, Mary Fisk, soon after.
Sadly, in this book, the pain of these broken relationships is something we hear about from the women only. "I saw the train wreck coming down the track," Fisk recalls of her husband's burgeoning affair with Rossellini.
Emily Stofle, whom Lynch married in 2009, describes their negotiations on starting a family. "I have to do my work and I don't want to be made to feel guilty," she remembers Lynch telling her. It's an admission that would be startling to read in Lynch's own portions of Room to Dream, which are as gnomic as you'd expect, sometimes frustratingly so. "Relationships are like films," he tells us. "People come and they go."
If anyone tends to stick around, it's Lynch's actors. They have the time of their lives working with him, and return to the fold whenever possible, like the many favourites who graced the mesmerising third season of Twin Peaks last year. Not only were Kyle MacLachlan and Laura Dern reunited on screen after 30 years - so was everyone, from Naomi Watts to Grace Zabriskie, Harry Dean Stanton and Everett McGill.
Lynch's sets are charmed spaces, and his whole career, he says, has felt benevolently guided, overseen by some cosmic sense of purpose. It's hard to disagree. As a young man with only one feature to his name, the avant-garde nightmare that was Eraserhead (1977), he was entrusted, amazingly, with The Elephant Man(1980) by Mel Brooks, who gave him sanctuary all the way, intuiting the genius he would absolutely bring to it. Lynch's salvage job on Mulholland Drive (2001) - a rejected TV pilot that he rejigged into a critically adored masterwork - has gone down in legend.
Even the ignominy of Dune (1984) - on which he "died twice", having compromised on his own goals, and then not delivered a commercial success - had a vital upside, in introducing him to the producer Dino De Laurentiis, who stabilised the ship by giving him absolute carte blanche on Blue Velvet.
David Lynch has never lacked room to dream, for which we and he must thank our lucky stars.
Room to Dream by David Lynch is available on the Telegraph Bookshop for £20