Jeannette Walls's 2005 memoir about being raised by two of the most unbelievably dysfunctional parents in American literature spent 261 weeks on The New York Times bestseller list, making a feature-film adaptation inevitable.
But Walls, who is now 57 and lives on a sprawling farm in the verdant, rolling hills of Virginia, never wanted to write the script for The Glass Castle.
"If it came up I just immediately dismissed it. I'm too close to it. This is not my medium. I don't understand moviemaking," Walls said over the phone in an interview to promote the film, opening this week.
There is no simple formula for how to adapt a book to the screen. If there were, there wouldn't be so many failures to point to, including movies based on hugely popular memoirs and other non-fiction works. But just as it is inevitable that bestsellers are destined for the screen, so too will the harsher edges of books be sanded off or outright ignored in favour of a more audience-friendly sentimentality. Director Destin Daniel Cretton's adaptation avoids easy moralizing, but this is a much less harrowing and much more heartwarming story than the one readers are familiar with. And Walls is fine with that.
"I was prepared to have some squirmy moments. And when the credits were rolling I was, like, fist-pumping the air. I just thought it was fabulous. I was overjoyed," she said.
Of course, differences between the source material and a film are to be expected. No adaptation can be perfectly faithful. Many scenes from Walls's book have been cut or slightly altered. Yes, we see her alcoholic father often neglecting his four children and then trying to win back their love with his promise of building them a wonderful house made of glass; an improvement, by far, over the dumpy shack with a garbage pit out front the family eventually settles in to.
But you won't see Walls as a child having to scavenge for food in garbage cans. Nor will you see arguably the book's most brutal scene, where Walls's younger sister stabs their mother in the neck.
Cretton, who has two previous features under his belt – Short Term 12 and I Am Not a Hipster – clearly understood that piling on the hardships of Walls's upbringing would be too much for audiences to bear.
The scene in which Walls's father forces her to learn to swim by repeatedly plunging her into the water made it into the film, but the one in which the parents make the kids ride in the back of a U-Haul truck that they are nearly flung out of when the door opens on the road was left on the cutting-room floor.
Walls saw the footage and was enthralled by it. She asked Cretton how he could possibly not include it.
"He just knew what would work on screen better than I did," she said. "He explained to me it would have come right before the pool scene. The viewers would be exhausted. It would feel almost like child abuse."
Whatever audiences make of the film, Walls has no complaints.
"Destin really got the story, and he got the love, and I was just really grateful for that," she said.
In our 20-minute conversation, Walls gushed about every aspect of the film – the director, the actors, even the set design. In that respect, the movie is unquestionably a success. (Frank McCourt, she said, was definitely not happy with the adaptation of his memoir Angela's Ashes).
The movie will likely also be a hit with audiences as well. Woody Harrelson is perfectly cast as Walls's reckless and charismatic father, Rex. Naomi Watts turns in a solid performance as Walls's mother, a woman who would rather paint than feed her children. And who wouldn't want Oscar-winner Brie Larson to play them in the movie of their lives?
None of us, however, will probably find the film as cathartic as Walls herself did. The first time she saw Woody Harrelson on set, she hugged him and apologized for putting him through a particularly difficult scene.
"He said to me, 'You had to do it, honey. You had to do it or we wouldn't be here.' And he said it in my father's voice. It was like being forgiven by my dad all these years later," she said. "It was very healing."
Perhaps this is what we all want most of adaptations of stories such as Walls's: to see many of the grim and damaging elements, but most of all to feel uplifting triumph over hardship. That way, we might be able to see our own lives in a more positive light.
"My hope for [the film] ultimately is that it will cause people to think about their own stories," Walls said. "I just believe in the magic of storytelling."