But it should come as no shock.
The actress has been building her career since she was young, as evident in her many TBT Instagram posts, and she's not new to picking roles that interest her.
I feel lucky that I have this life when it comes to art that's allowed me to look deeper into myself. When I take on different characters, I either learn new things about myself or I remind myself of a person that I was before. Which is part of why I love doing those throwback posts. We're on this really long, awkward journey and I think for women growing up it's really lonely.
But "growing up" doesn't mean playing the adult.
When asked if she had any tips for Millennials to "fake it 'till you make it," Larson said simply -- don't -- which may calm your fears of "adulting."
But why do you have to be an adult? That's the part I'm so confused by. To me, once I got too serious life became incredibly less fun. I wasn't enjoying being in my body, or being with friends, or having a good time or enjoying my journey. No one knows anything. That's the thing I remind myself of. Even Oprah. She knows just as much, she's just on a journey like everybody else. Everyone's taking twists and turns along the way. It's okay. I think if we can just embrace the fact that things are gonna get a little weird, then we'll be okay.
In "Free Fire," Larson appears as the only woman, alongside Armie Hammer, Cillian Murphy, Sharlto Copley, Sam Riley and a crew of other trigger-happy men in a warehouse set in 1970s Boston.
Directed by Ben Wheatley, who also co-wrote the movie with his wife Amy Jump, "Free Fire" turns the genre on it's head.
It's as serious as it is slapstick, and making fun of this violent genre is what originally drew Larson to the script, along with the role of Justine.
The glorification of violence in movies is something that's very twisted and interesting and, I think, very pervasive in our culture. The opportunity to kind of twist that genre and make fun of it seemed like a really great idea. I also think any time I get to play a woman that's different in a action film, that is showing a different side of what it means to be a woman, is something I'm interested in. Not just tough, but multifaceted.
You can catch "Free Fire" in theaters on April 21, 2017.