Saoirse Ronan has revealed how moving away from home was a more powerful experience than she had expected.

The 20-year-old actress drew on her own experiences of leaving home for her new film Brooklyn, where she plays a young woman leaving her Irish hometown for the US in the Fifties. The movie is the big-screen adaptation of Colm Toibin’s novel of the same name.

“It was probably about eight to 10 months before we started doing the film that I had moved away. It was my first time moving away from home,” she said at the film’s premiere at the Sundance Film Festival.

“I kinda assumed it would be fine because I’m always working away, but it’s a very different thing living in a flat on your own, paying your bills without that stability. When you’re hungry, you have to go out and buy food.”

The Irish actress added: “It’s crap, all that stuff. It’s like, growing up is shite. I’m sure you get there eventually but I’m not loving it yet.”

Saoirse Ronan and mother Monica
Saoirse and her mum Monica (AP Photo/Amy Sancetta)

Saoirse continued: “I guess I was just going through all that stuff at that time and I’ve never had that before, and it made the whole thing very emotional. I’d never worked on something where I couldn’t quite manage how I was feeling. It always affected me and it still affects me.”

Saoirse Ronan, Emory Cohen and John Crowley
Saoirse with her Brooklyn co-star Emory Cohen and director John Crowley (Chris Pizzello/Invision/AP)

The Hanna star was attached a year before the movie started shooting, and said she felt compelled to be involved.

“I changed an awful lot in that year when I read it to when I made the film,” she explained. “I had gone through so much myself.

“I thought, ‘I have to do this because it’s my life in a way’. It’s very much my story and my parents’ story. I’m very proud to be where I’m from and to be representing so many generations of Irish people and other immigrants who moved over to New York. It’s pretty special.”

Saoirse Ronan and John Crowley
John Crowley was impressed by Saoirse Ronan (Dan Steinberg/Invision for The Hollywood Reporter/AP Images)

John Crowley, who directed Brooklyn, heaped praise on his leading lady.

“In the time when I first met Saoirse about this project to when we started shooting it, she left home and moved to London. She was really struck by how powerful an event that was in her life, in the way she wasn’t expecting it,” he said.

“That’s what the story spoke to – the primal wrench that happens to someone when they leave home. She met that role in a way that is incredible. I’ve never seen an actor’s life and the role they are playing set so beautifully as with Saoirse in this role.”