Hammer, who had been floating around on various television projects for the bulk of his acting career, landed roles as twins Cameron and Tyler Winklevoss, partial creators of Facebook.
The then-23-year-old actor was tasked with not only bringing his best acting for his breakout film, but duplicating it for a separate character.
"It was weird and it was tough initially, especially the first couple days trying to figure out how we're going to do this, creating a system and all that," Hammer details to then-correspondent for ET and current omg!Insider co-host Kevin Frazier.
"[It was] surreal because I felt like the smaller triplet. It was so strange," he says. "...It was after production when we'd met 'em, so I'd spent the last eight months trying to think like these guys."
"...So to finally see them I was like, 'Dude, Cam, remember when you were 15 and you fell in the water?' and Ty, 'Your mom was like "Oh, I'm so mad at you guys!"' and they're like 'We just met you. You are freaking us out, dude. Pump the brakes!"
Despite his encyclopedic knowledge of their lives, the Los Angeles native, who took the risk of forgoing an education in order to pursue his acting career, says he doesn't relate too much to his characters in the film.