You could replace the last word of “A Complete Unknown” with any number of seven-letter words and it’d apply to the hero of James Mangold’s new film, the young Bob Dylan (Timothée Chalamet), whose callowness is seen with piercing clarity.

Dylan fans are used to this side of their hero, most cuttingly observed in D.A. Pennebaker’s documentary “Don’t Look Back,” but neophytes may come into the film liking Dylan a lot more as an artist and a lot less as a person.

The film opens with Dylan arriving in New York in 1961, backlog of masterpieces in tow, and it ends with his explosive performance at the Newport Folk Festival in 1965, when he shocked the folk establishment by performing with an electric blues band.

Focusing on such a narrow window of Dylan’s career offers Mangold two advantages. First, he immerses us in the Greenwich Village folk scene of the 1960s, a milieu where you could see a pretty good set by someone like Bob Neuwirth (Will Harrison) in any club, bar and cafe on any given evening. Mangold captures the excitement of having a backstage pass to a cultural shift, and it’s a shock to realize that even elders like Pete Seeger (Edward Norton) and Woody Guthrie (Scoot McNairy) were still only in their 40s at the time.

The second advantage of this zoomed-in focus is that it allows Mangold to break free of the rhythms of a conventional biopic, though it would’ve been difficult to make one about Dylan anyway. Rather than rushing through historical events with quick-cut montages, Mangold leaves time for Dylan to simply play his songs, and though we hear hits like “Blowin’ in the Wind,” we also hear obscurities like his absolutely shattering 1961 song “I Was Young When I Left Home” in more or less their entirety. (If you haven’t heard Anohni and Bryce Dessner’s version of that song, released on a 2009 AIDS benefit compilation album, seek it out immediately.)By ending at Dylan’s early peak at Newport, “A Complete Unknown” ends where most films would show the hero beginning to descend into hubris and bad decisions. Dylan’s career hasn’t really been like that. Instead, he’s been allowed to continue playing the cosmic joker, confounding interviewers and concocting insane backstories, apparently exempt from the obligation to learn or grow as a person.

“Dylan became the first songwriter to win the Nobel Prize for literature,” a note approvingly tells us at the end. “He didn’t show up to the ceremony.”

We watch Dylan grow not so much into his art as into his cruelty. Like his friend John Lennon, he was so good at insults he must’ve felt like he was signing a work of art every time he said something especially cutting to someone.

His decision to go electric is framed not so much as an artistic decision as a giant middle finger to anyone who wants to put him in a “box” as a protest singer. Though his intuition to use traditional folk forms to reflect the fears of the ’60s made him a spokesman for his generation, his engagement with current events seems limited, and we often see him turning off the news when someone else has it on.

Who is he really? Who does he really want to be? We never really learn, but while that’s the question Dylan’s built his art on, it doesn’t make for a very pleasant person to spend two hours and change with.

Gangly and chain-smoking, painfully inarticulate when he’s not in front of a microphone, he skulks through the streets of Greenwich Village slagging off girlfriends and pissing off the people who helped him break into the folk-revival scene he would soon help destroy.

Dylan’s status as an aspirational Peter Pan figure is key to his art, but stuck with him in the theater it’s easy to become as exasperated as all the people whose enmity he earns in the film, from girlfriends like Joan Baez (Monica Barbaro, who grew up in Mill Valley) and Sylvie Russo (Elle Fanning) to mentors like Seeger (whose arguments for the preservation of the Newport Folk Festival and its acoustic tradition I found much more convincing than the mumbled rebellion-speak with which Dylan explains his new sound).

The best argument the movie makes for Dylan’s decision to go electric is simply the split-second look Johnny Cash (Boyd Holbrook) makes in response to Dylan’s set. He’s absolutely over the moon to be at the 1960s equivalent of the premiere of “The Rite of Spring,” and I felt a rush of gratitude for artists at that moment, but on account of Johnny’s joy, not Bobby’s impudence.