(CNN) -- Released in time for John Lennon's 70th birthday, Sam Taylor-Wood's moving film is a portrait of the rebellious future Beatle on the brink of breaking rock 'n' roll wide open.
In 1956, Lennon is 16, a cheeky, smart-mouthed Scouser (Liverpudlian) who is beginning to run into trouble at school, especially after the death of his beloved Uncle George.
Lennon (played by Aaron Johnson) has grown up in the care of Aunt Mimi (Kristin Scott Thomas), a prim and proud lower middle-class housewife -- a woman who brushes off any overt displays of emotion with a gentle scold: "Don't be silly," meaning life is too punishing to relax our defenses even for a moment.
That's not Lennon's way.
Coming of age in the austere post-war years, he's hungry for fun -- girls, for instance or riding the roof of a double-decker bus or listening to the American 45s he picks up cheap at the docks. But it's only when he's reunited with his real mum, "the red-haired one," as he refers to her early on, that music becomes his main focus.
Screenwriter Matt Greenhalgh ("Control") puts that reunion in the wake of George's funeral, but in reality she had been a regular visitor at Mimi's house. Played by Anne Marie Duff, Julia is Mimi's polar (or bipolar) opposite: an effusive, flighty good-time girl who showers John with so many kisses her second (or is it her third?) husband has to bite his tongue.
Sensual and uninhibited but borderline manic-depressive, Julia seems ready made for rock 'n' roll. Put a shilling in the jukebox, and she'll dance in front of a roomful of strangers, the kind of display that could only harden Mimi's conviction that she is no fit mother for the wayward boy.
When Lennon shows up with a Screamin' Jay Hawkins record, they listen to it together and Julia's rapt reaction is almost as inspiring as the song itself. Expelled from school for a week, he takes refuge with his mum and she puts a banjo in his hands.
The rest, as John might say, is his story. He forms a skiffle band, The Quarrymen, and soon makes the acquaintance of baby-faced Paul McCartney.
A distinguished photographer and conceptual artist, director Taylor-Woods keeps it simple in her first feature film. And if she occasionally seems stranded by the script's bald determinism (Greenhalgh condenses and distills with too much vigor sometimes), she's equally sensitive to the emotional claim of each sister, as well as to the troubled adolescent who feels himself torn between them.
You might expect Mimi to be the villain in this scheme, but while Paul McCartney has noted that Mimi was less starchy than she seems here, Kristin Scott Thomas delivers another superb, subtle and ultimately deeply sympathetic performance that makes Mimi the movie's unlikely center of gravity.
Johnson -- who made "Kick Ass" after this -- probably wouldn't win a look-alike competition and soft-pedals the hard Scouse accent, but he catches Lennon's turbulent brilliance, his swagger, wit and anger.
The movie reminds us just how much he had to be angry about, and suggests very movingly that before he preached universal peace and love, he had to find it within his own heart.
"Nowhere Boy" may be modest in scale, but Beatles fans will recognize that it's made by one of their own.