The lore that’s already been built up around Barbie has taught us that star Margot Robbie was instrumental from the very beginning in bringing the fashionable Mattel doll to the big screen. But apparently, co-star Ryan Gosling—who plays Ken—took a bit more convincing to join the project.

Talking to Rolling Stone, Barbie director and co-writer Greta Gerwig explains that Gosling was her only choice for Ken, even though she’d never actually met him. “It was only ever Ryan Gosling, and it was a long journey. Margot and I just wouldn’t take no for an answer,” Gerwig said. “From the moment that Margot came to me and I knew we were making this for Margot, I equally knew we were making this for Ryan. And I did not know Ryan at all. I’d never met him. I just was sure, and as soon as I thought of it, it made me so happy. Who else could do this? It’s some combination of Marlon Brando meets Gene Wilder meets John Barrymore meets John Travolta.”

Gerwig calls Gosling “a secretly comedic actor” who succeeds by taking comedy very, very seriously. “The way we talked about Ken was as in-depth character work as I’ve ever done with anyone about anything … I don’t know that anyone has ever invested more in making people understand the plight of this man. It was extraordinary,” Gerwig said. “I felt with both of them that I might direct movies for a long time and never see anything that uniquely and gloriously unhinged.”

Head to Rolling Stone to read the full interview, which also includes the tidbit that Gerwig is absolutely open to making a superhero movie—“It would have to be something I had a feeling for and a relationship to”—even though she agrees Barbie is already sort of a superhero movie: “It’s iconic in the same way. And it’s sort of mythic in the same way.”

Barbie opens July 21.

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