By Hayley Mills' reckoning, it was the "role that got away." At age 14, the British actress was approached by Stanley Kubrick to star in the film version of "Lolita." "I could see it was a good part," she recalls. She even saw a bit of her innocent self in Nabokov's nymphet: "She was teetering on the brink of womanhood, like me. … She wants her own way, she's moody, she wants to be treated like a grown-up, but behaves like a child. I got all that."

Mills' parents turned down the role, and if they hadn't, it's a safe bet that her employer, Walt Disney (having already vetoed her for "Exodus" and "The Children's Hour") would have sent both Kubrick and protagonist Humbert Humbert packing. "Disney's daughter," as Mills calls herself, remained Disney property.

Incidents like these form the heart of Mills' "Forever Young," an affectionate but clear-eyed memoir of an unusual career that began at 12, swelled to global proportions during puberty and then, in young adulthood, dwindled into something quieter. Happenstance played some part in that journey, but so did genes. Mills' father, John, was a highly regarded actor; her mother, Mary Hayley Bell, a novelist and playwright; her older sister, Juliet, a former ballerina and ascending actress.

Young Hayley, by contrast, was a tomboy with big teeth and "a nose someone once described as a lump of putty." Even when she was cast alongside her father in a British indie called "Tiger Bay," she shrugged off the critical plaudits, she says, put aside any thoughts of career and went back to tearing around her family's 14th-century Sussex farmhouse.

In the way of miracles, a print of the movie reached Walt Disney, who was looking for a young actress to headline his next picture, "Pollyanna." Calls were made, and Mills ended up converging on the great man's London hotel room with her parents, her brother and a Pekingese puppy (gift of family friends Vivien Leigh and Laurence Olivier) that kept threatening to pee on the carpet. Walt looked, listened, smiled, nodded. "It was the nicest casting meeting I've ever been to," Mills writes, and it ended with her being offered an exclusive seven-picture deal.

In short order, Mills was disembarking on a tarmac under a shimmering L.A. sun. "The beginning of hell," her mother whispered, but, for Mills, "it felt like home. The camera gives you its total, undivided attention; it doesn't judge, it's just there, quiet and steady, to observe, absorb, and to listen." For her next film, she played identical-twin sisters with (unexplainable) British accents who have been (utterly and bizarrely) separated by their divorced parents only to bump into each other (fantastically) at a summer camp. None of the parentheticals mattered. "The Parent Trap" was such a success that "Let's Get Together," the execrable song that Mills was forced to sing in it, became a Top 10 hit.

An album followed, and more movies. Money, too: Mills was able to buy a French villa shortly after her 18th birthday (though British tax authorities would later confiscate most of her prematurity earnings). She flirted with a Greek film director in Crete, hung out with Paul McCartney and Jane Birkin, fought off mobs of fans in Japan and went on a date with George Harrison that fell apart before even larger mobs: "a snake pit of shrieking, scratching, maniacal girls."

Through it all, she was haunted, "Parent Trap"-style, by an identical twin, "staring back at me: an image projected by my movies, by the Disney publicity juggernaut, by the hundreds of interviews, magazine stories and articles, which combined to create a character that I didn't even recognize."

Perhaps this is why, looking back as a 75-year-old, Mills can be tart about her former employer: "When it came to dealmaking, the Mickey Mouse Club took no prisoners." She can also be refreshingly honest about her mother's alcoholism, her own bulimia and her troubled first marriage to Roy Boulting, a film director 32 years her senior. ("I had merely substituted one straitjacket for another.")

About later relationships and struggles, Mills remains mostly mum for, as the title suggests, this is the story of a girl — a girl for whom Disney Studios represented "home." Walt himself lingers in memory not as a racist or imperialist or anti-Semite, to cite some of the postmortem judgments, but as "my boss, my mentor, my friend … a father figure."

After Mills had shot her last Disney picture, "That Darn Cat," Walt sent her a farewell letter: "You know that old saying about not losing a daughter but gaining a son … well, this is sort of like losing a daughter and I didn't gain any son to make it worthwhile."

In the face of such family feeling, how could Lolita have stood a chance? From this angle, it's instructive to sit down once more with "Pollyanna," which earned Mills the last Juvenile Oscar ever presented. (She didn't know. Her parents had bundled her back into her British boarding school.) The movie's premise is ominous — an orphan transforms a grim New England town into a kind of antidepressant commercial — but young Hayley Mills makes it work. Never cloying, she comes at her role simply and without affectation, and suggests that happiness is less birthright than stubborn spiritual discipline. Maybe that girl didn't need to meet Humbert Humbert.

Louis Bayard is the author of "Courting Mr. Lincoln" and "The Pale Blue Eye."