In a strange way—though not so strange, considering his legacy—David Bowie divined his own death. Back in the 1970s, the singer was traveling across America on a tour bus, on the road to support his album Aladdin Sane. He turned to his longtime pianist, Mike Garson, and uttered a strange prophecy: “I’ve had a dream that I’m gonna die at the age of 69.” Sprint a few decades ahead, and Bowie did in fact die of cancer, just two days after his 69th birthday.

The dream anecdote was told by Garson to director Francis Whately, the filmmaker behind the new documentary David Bowie: The Last Five Years, which focuses on the musician’s work in the later years of his life and premieres on HBO Monday.

“It was very chilling because of the way Mike talked about it,” Whately tells Vanity Fair. “They talked about it again 20 years later, and David said, ‘I still remember that dream.’”

Whately, a self-described super-fan, first met Bowie nearly 20 years ago, when the singer was tapped to do voice work for a film Whately was working on. He was small and unassuming, the director recalls, which surprised him. Then again, “it would have been ludicrous for him to dress [as] Ziggy Stardust.”

The session almost went off without a hitch, until Bowie mispronounced the name of the painter Percy Wyndham Lewis—and Whately had a small internal crisis over whether he should correct David Bowie. “I was paralyzed,” he recalls, though he eventually gulped down his fear and asked the star singer to re-do the name. Bowie responded by shrugging and saying, “All right. You’re the boss, Francis,” which immediately put the director at ease.

Director Francis Whately photographed during the New York premiere of HBO's David Bowie: The Last Five Years. By Michael Loccisano/Getty Images.

The pair enjoyed a fulfilling correspondence over the next two decades, e-mailing book and film and art recommendations to each other. Bowie was a fan of Andrei Tarkovsky and Junot Díaz’s novel The Brief Wondrous Life of Oscar Wao. He even watched and gave feedback on all of Whately’s work, including the previous 2013 documentary David Bowie: Five Years, e-mailing Whately straightaway to let him know “how proud” he was of the film.

“Until he passed away, there was no one who saw as much of my work as he had,” Whately says. “He was very generous about what I made, and he always critiqued it and said what he thought.”