When Ellar Coltrane was auditioning for the role of Mason as a 6-year-old, Richard Linklater was more interested in the resilience of his parents rather than the acting skills of the young protégée that would become the centrepiece for his most audacious film yet.

Patricia Arquette, Ellar Coltrane, Richard LinklaterPatricia Arquette, Ellar Coltrane, Richard Linklater at an Academy screening of 'Boyhood' - Photo: Getty 2014/Michael  Loccisano

This is because his parents would have to keep this young actor interested in the role of a lifetime, spanning 12 years and shot for only three days per year. Ellar Coltrane got the part, and as we watch Mason grow up before our very eyes, a 19-year-old actor owes a huge part of his upbringing to the process of filming ‘Boyhood’. 

More: Boyhood: The "Tremendous Risk" That Came Good at This Weekend's Box Office

"I've undergone more physiological and emotion development in the past six months than I have in the past six years. The first couple times I watched, it was hard to really think much. There were so many emotions and curiosity that had been building up for so long,” explained Coltrane to Teen Vogue. 

“Everyone as a teenager struggles with self-identity and feeling real and important and valid. We feel really disconnected from ourselves and everyone around us, and to see all these little parts of myself that taken out of context might be embarrassing or awkward, but seeing it all put together like that is very comforting. It's terrifying, but it's actually proof that I'm real."

Watch the trailer for 'Boyhood'

The film stars Ethan Hawke and Patricia Arquette, who play Mason’s divorced parents battling through their own personal lives. "The long nature of the project allowed a lot of us to become very lost in the artistic process and forget about the end goal of it being a movie and people watching it," he explained. "Most of the project was kind of distant. The purpose of doing it was to do it."