Jonathan Glazer, director of three exquisitely distinctive feature films and adman and music-video-maker extraordinaire, turns out to be far from the slick operator you may have supposed him to be. The veteran of – presumably – a thousand pitch sessions, and hundreds of media interviews is halting to the point of reticence on the phone when I call up to tell him Under the Skin is the Guardian critics’ pick for best film of 2014.

“I’m ... very … appreciative,” he mumbles, sounding almost embarrassed. “It’s very … encouraging.” Encouraging? If this is a man who needs encouragement, surely we’re lost. But no, Glazer does not appear to obviously possess the nerves of steel required to make the dynamic, idiosyncratic productions that he is renowned for. He says the first screenings of the finished film – at Telluride, and shortly thereafter at Venice – were “nerve-wracking”. “You do something in isolation, and get prepared for a lukewarm response. I remember thinking: there were far fewer supportive than negative ones. The Guardian was about the first place to come out in its favour.”

That’s certainly true, with Xan Brooks’ five-star review from Venice sounding a clarion call of appreciation.

Much has been written and said about Under the Skin’s tortuous progress to the screen, so there’s little reason to rehash that again; more to the point; will Glazer take another decade before he puts out another film? “I’m getting on with things; but I’m still not entirely convinced I’m a career film-maker,” he says. “I feel kind of outside of it all. Unless something catches fire I don’t feel any urgency. You audition an idea in your head, and live with it for a while; if it sticks, then on you go.” Happily, Glazer admits “there is something I’m thinking about at the moment”, but won’t go into details.

Whatever the future holds for Glazer, Under the Skin remains an extraordinary achievement, its out-of-body strangeness somehow befitting its 13-year gestation period. With hindsight, I ask, did the project benefit from such a drawn-out process? “I think it did. It took all that time to rinse it out, and make sure it was what I wanted to be. I felt ultimately that I’d completed what I set out to do, for good or bad. ”