The Glass Castle is about the author's chaotic, complex relationship with her unconventional father (played by Woody Harrelson). Larson said that the screenplay touched a nerve. "I think it has to do with family being complicated and having lots of negatives and positives," she says. "I feel that life is like that. You don't get to pick and choose what parts of life you get, you just get all of it. I think a lot of us feel like we're not allowed to be at the completeness of who we are. And I want to encourage more people to feel like they can be complicated."

Brie Larson in The Glass Castle

She feels like Walls' story is an inspiration in this sense. "What would happen if we were all just everything we are and threw out rules and ideas about what everyone thought we were supposed to be?" she says. "That doesn't mean we're the most traditionally great parents and supportive in the way everybody needs. You're just yourself."

Meanwhile, Larson has finished filming her directing debut Unicorn Store, which arrives in cinemas later this year. "For me, the idea of directing is not about success for me personally," she says. "It's about putting more pieces on the board. So my hope is that women can watch it, and they can go like, 'If she did that, I can do better than that.' I just want women to feel like they can take the risk. Actually, it's not even just women: it's everybody who wants to do something and feels like they're not allowed to do it."

Larson says she's the kind of person who likes to constantly challenge herself. "There are still these parts of me that are like, 'Am I allowed to do this? Am I allowed to just like be a free, creative person and just try?'" she says. "And I'm realising as time goes on that I am, and so I hope that other people get that."

One upcoming challenge for the Oscar-winning actress is to play the most powerful superhero in all of the Marvel Comics: Carol Danvers, better known as Captain Marvel. Larson is looking forward to diving into the role, admitting that she has one person she'd really like to face off against. "I do kind of have fantasies of battling the Hulk," she laughs, "just because that's like, it's just visually so good!"

Watch the trailer for The Glass Castle: