Long before he was cast in Rogue One: A Star Wars Story, Luna, 36, starred as Katy's tragic love interest - and it changed his life.

"This is before Star Wars but more people have seen that video than the people that have seen all my other films together. It's just insane," Diego laughed to People.com about entering Katy's world. "I didn't know what I was stepping into. This whole world of pop - it's so intense and it got everywhere."

Despite having then starred in critically-acclaimed films like Frida, Y Tu Mama Tambien, and Milk, Diego insists he could easily walk around without being bothered - before Katy came along.

"I became 'The Guy from the Video,'" he explained. "In places where I used to just walk around without getting any attention, suddenly people were like, 'Oh my God, the guy from the video!'"

He still can't believe he filmed for only two days on what would become a phenomenon, but he remembers having a very good time in the process.

"There was a lot of partying going on so it was a little like a 20-hour party," he smiled.