Who is Woody Allen?

Early on, in a new documentary about Woody Allen, the cultural icon sits in the back seat of his chauffer-driven car, pondering his mortality. He tells a story of a formative near-death experience that occurred when he was a small child in his crib: His mother was at work when his nanny told him, and then demonstrated, that if she wanted to, she could smother him. For a few seconds, she wrapped a blanket around his face.

More than seven decades later (Allen turns 76 on Dec. 1), Allen still wonders aloud how close he came to the bitter end on that bizarre day. Had that nanny made good on her threat, a stony Allen deadpans: “The world would be poorer a number of great one-liners.”

In the three-hour-plus documentary of his life, which airs in two parts as part of PBS’ American Masters series beginning Nov. 20, those words are the closest Allen comes to acknowledging his own legend.

“So much of what’s filtered out about me over the years has been completely mythological,” he tells the camera.

His mystique has proven gripping for Allen’s legions of fans, who have faithfully followed his zigzagging mind through a prolific film career that has been variously comic, wacky, poignant, dark, charmingly romantic and almost ludicrously intelligent — all of which is on display in this biographical film. Nor does Allen’s neurotic self-effacement hold sway with the documentary’s producer, Robert Weide, best-known for his five-year stint as an executive producer and principal director of HBO’s “Curb Your Enthusiasm.”

“The big thing with Woody was getting over the hump of him agreeing to do this in the first place,” Weide said during a phone interview. “That hesitation was about him feeling that he wasn’t an interesting subject — that’s how out of touch he is.”

The film frequently acknowledges, through Allen’s friends and colleagues, that he is one strange genius. Recalling Allen’s early career doing stand-up in the West Village, his manager, Charles Joffe, observes, “He could hardly talk to people, let alone perform for them. And some nights, he was godawful. But other nights, he was absolutely brilliant.”

What Weide has woven together is the most intimate portrait of Allen ever shown. Viewers are invited into his mind and even his bedroom, where, for example, he shows Weide his “idea drawer,” splaying atop his bed pages upon pages of legal paper scrawled with story ideas. Allen also shows the ancient German typewriter he bought for $40 when he was 16, with which he has “written every script, every New Yorker piece, everything I’ve ever done.” For the first time in his 40-year film career, Allen also allowed a camera to follow him on set. The 2010 film “You Will Meet a Tall Dark Stranger” did not prove popular in the Allen canon, but its production offers a gift: Allen can be seen in his simple, directorial glory, casually instructing actors Naomi Watts and Josh Brolin as they rehearse a scene. In Allen’s presence, glamorous movie stars become deferential, timid and eager to please.

Courtesy of Brian Hamill/©MGM

But just who is Woody Allen? Brilliant comedian? Prolific writer? Legendary auteur? He’s also developed a following as a jazz clarinetist — but those designations only describe his talents. Pinning down his personality, his identity, his character is far more complicated, yet that is the part of him we most want to know. What sort of person lurks underneath the artist? Allen’s public persona has run the gamut: neurotic, self-deprecating genius; asocial agnostic; hopeless romantic; selfish cad. If he were writing the script, he might portray himself as an ordinary family man — he has, after all, been married for almost 15 years to Soon-Yi Previn, with whom he has two children — but this now seemingly normal life was born of one of the most sensational romantic scandals of the 20th century.

Even after a reported seven sit-down interviews with Weide, conducted over two years, Woody Allen remains an enigma. His psyche is exposed, but not entirely understood; if he has wrestled with the pain he caused, those struggles remain private, concealed behind the veil of his public disgraces. This documentary, Weide said, was not intended as psychological portrait, but as a portrait of Allen’s career. Indeed, Weide shows himself to be a fan, his film “a public thank you” to an artist he has long admired and not a revelation about Allen’s cultural impact. “To me [his private life] is the least interesting thing about him, and this was going to be a film about his work. It would deal with his life to the extent that it informs his work,” Weide said.