It was only after Mara Wilson played innocent-faced little girls in movies like Mrs. Doubtfire and Matilda that she discovered the allure of anger.

"I was riding in my brother's friend's car, and I was 9 or 10, and they had Bikini Kill on," she recalls. The Olympia punk band, known for songs like "Suck My Left One" and "Don't Need You," was a revelation to her. "I remember thinking to myself, 'Is that a girl singing?' and being kind of fascinated and terrified at the same time. And being really into it."

At the time, her mother had just passed away, and Wilson was struggling with untreated anxiety, depression, and obsessive-compulsive disorder. The longer she stayed in Hollywood, the worse it felt. "I'm not very good at being glamorous," she said. "Fame always felt strange to me. At least that kind of actress-fame. It was never a top priority for me, and when I did achieve it I didn't really know what to do with it."

Not long after, Wilson left Hollywood behind, and she's now known for a witty Twitter presence with more than a quarter million followers. She also has a new book, Where Am I Now?, and she'll be stopping by Town Hall Seattle on September 21 at 7:30 p.m. to talk about it.

"Seeing people who were able to channel anger into something positive, something creative—you actually see that in Matilda," Wilson said, describing how feminist punk music aligned surprisingly well with a character she'd just finished portraying. "She channels that anger into fighting injustice. I think that stuff was very helpful to me... I didn't see a lot of girls who were angry. And I didn't see a lot of girls who were scared the way I was."

On-screen, Wilson's characters exuded bravery and intelligence. "I don't think I realized it at the time, but Matilda became something of a cult movie for young women," she said. (For young men, too; one of my friends recently told me how Matilda's lesson that adults can be fallible helped him reconcile with his mother after he came out.)

The memoir was motivated, in part, by her longtime fans. "They were all curious where I had gone and what I had done," she said. "And I wanted to explain it on my own terms."

So where did she go? Into the written word. "I always wanted to be a writer," she told me. "When I was working on sets, I was writing plays and screenplays and stories behind the scenes. That's what I was doing in my trailer."

Wilson used her movie money to attend a boarding school for the performing arts. "I wanted to run away from Hollywood and do community theater," she said. From there, she attended NYU, and wrote and performed an autobiographical show. That's when she realized: "Oh, wow. This is what I am meant to do. I'm meant to write."

Like her fans, Wilson counts Matilda among her inspirations. "I felt like I was paying her tribute," she said. "She channels anger into fighting injustice. I think that stuff was very helpful to me."

Also on her list of inspirations: the character Lyra from the book series His Dark Materials, Beverly Cleary's Ramona Quimby, Judy Blume's Sally J. Freedman, Shirley Temple Wong from In the Year of the Boar and Jackie Robinson. Given the turmoil of her youth, it's not too surprising that her favorite movies include Blame It on Fidel, in which revolutionary forces strain a girl's family; Persepolis, about childhood during the Iranian Revolution; and This Is England, about conflicted young British skinheads. "And riot grrrl," she added. "I love riot grrrl."

These days, Mara often seems as unflinching as her literary heroes. She hosts a monthly live show called What Are You Afraid Of, in which people join her onstage to confess fears from spiders to mall Santas. As part of the show, Mara brings in experts on the topics to diffuse anxiety.

"We talked about my sister's fear about getting water in her ears... and then we talked to an ear, nose, and throat specialist," Mara said. "Learning about your fears takes the power away from them."

Anger and fear may seem like negative emotions when they rule us, but once tamed, they are powerful tools. Anger can be a means of propulsion to one's calling, and acknowledging a fear can illuminate our better selves.

Writing the book, Wilson said, "has been a lot about facing fear. I know I'm going to be out in the public eye again. That's a little scary for me. But at the end of the day, I have family and friends who support me, and like me no matter what. I just have to keep telling myself that."

Standard Hollywood fame was a mismatch for the little girl who wrote plays in her trailer, and the pressures of celebrity are enough to strike fear into any reasonable person's heart. But from her lived experience, Mara's learned to partake in fame on terms that work for her: "I'm surrounding myself with people who will tell me the truth," she said, "and who like me for who I am."