'Rules Don't Apply' co-stars Lily Collins, Alden Ehrenreich share what they learned from legendary co-star Warren Beatty

'Rules' stars Collins and Ehrenreich as a pair of wide-eyed young adults involved in a forbidden romance. Beatty co-stars as Howard Hughes.

At the heart of Warren Beatty's long-in-the-making "Rules Don't Apply" is a burgeoning but forbidden romance between a pair of wide-eyed young adults, freshly plucked from their traditional upbringings and thrust into the capricious world of Howard Hughes and 1958 Hollywood. Serving as distant proxies for Beatty's own Hollywood beginnings, Lily Collins stars as the innocent aspiring actress Marla Mabrey, a Baptist beauty queen turned one of Hughes' many female contract players, and Alden Ehrenreich as the ambitious Frank Forbes, who gets his start driving for Hughes and "his girls."

The two young actors reunited recently to discuss the unique process of working with Beatty and how his career and life choices have influenced theirs.

AP: What's the story of how you two met?

ALDEN EHRENREICH: We met in the context of Warren. We had never met before, but we grew up in the same town and knew a lot of the same people. Our moms knew each other.

LILY COLLINS: It's really bizarre that we never crossed paths until Warren getting us together to finally get in the same room.

AP: Your moms knew each other?

COLLINS: Through the Beverly Hills Women's Club. They used to be on the board together.

EHRENREICH: I didn't know my mom was on the board.

COLLINS: Yep, they were in the Women's Club together, and I think there was another club in Beverly Hills, and they used to spend time organizing events together and were constantly talking about each other's kids. I actually met your mom at one of those events. I remember hearing about this infamous Alden!

AP: Did you have any touchstones – whether a family member or cinema – for the time period of the film?

EHRENREICH: For me, it was so much growing up and watching all these old movies forever that that was just in my DNA. That's why I wanted to be part of this movie for so long, because I thought it was the closest opportunity to be part of something like that.

COLLINS: My grandmother was a ballerina during that period. She's no longer alive, but I remember referencing old photos of her. She had a lot of the same images that a lot of the Hughes girls had in their pictures, so I looked at those to kind of emulate her grace and how she carried herself. Otherwise I just watched old movies and took in the essence of those women and read chapters about the Hughes girls that he brought in from different states.

AP: Do you have a favorite Warren Beatty story?

COLLINS: I think for me, just the way in which I met him and the way I became associated with the project was bizarre. I was doing hair and makeup for a premiere of mine and my agent called me and said, "Here's a number, Warren Beatty wants you to call him at home," which was bizarre and crazy and strange. So I called him at home and the first words out of his mouth were "I told you never to call me at home!" Then he was like, "Just kidding, hi!" It started this tone of the entire experience which was organic but also the most unconventional thing I've ever been part of.

EHRENREICH: I spent five years just having dinner and lunch with him and there are so many different moments. I remember there was a time, like two or three years into knowing him, but he had read somebody for the film and I didn't know whether or not I had the role, but once he read this person, I felt like he'd become more fixed on him. So one night after dinner, I asked if we could read one of the scenes and not knowing whether I was going to be in the film or whether it was going to happen, honestly. We went back to his house and read the scene between (Forbes and Hughes) at the dock. We ended up reading it nine times into the night. I remember walking away from that thinking, well, if the movie doesn't happen or I don't get cast in the movie, I'll always have had that experience.

AP: What else do you think you'll take away from this?

EHRENREICH: For me it's the education that I got from Warren. Just understanding how he made the decisions he made in his own life, how he stuck to his own convictions and did things exactly the way he wanted to do them.

AP: He was one of the first actors to really take control – does that hold appeal for you?

COLLINS: I'd love to wear all those different hats at the same time one day. Learning from him was a huge opportunity. He was one of the first to do all of that in a time when actors were just actors. Also, to see Annette (Bening) have the amazing career that she has but also have this incredible family and the kids who they have are so intellectual, kindhearted, and witty young people? To see that you can have both is amazing, because I want both and it's proof.