Fatherhood helped Casey Affleck film Manchester By the Sea
Casey Affleck couldn't have made 'Manchester by the Sea' if he wasn't a parent.
The 41-year-old actor - who has sons Indiana, 12, and Atticus, nine, with estranged wife Summer Phoenix - stars as janitor Lee Chandler, who returns to his hometown after his brother dies in order to be guardian to his nephew, and the move brings back past memories, including the deaths of his kids in a fire he inadvertently caused.
And Casey needed to draw on his own feelings as a father in order to understand his character.
He said: "I don't think I would have been able to do this if I wasn't a parent.
"It makes it harder because you're living that nightmare, you're falling down the rabbit hole and indulging thoughts that are more horrifying than you've ever contemplated - that worst case scenario.
"Saying that, this was the dream role. Working with a team this talented, you feel safe driving down that road where you can lose yourself and be a wreck and be miserable and know you have that support."
But Casey is unsure whether the breakdown of his marriage - which was coming to an end during filming - had any impact on his performance.
He told OK! magazine: "I don't know. It sounds crazy, I acknowledge that, but your body doesn't really know the difference between experiencing something for real and convincing yourself you're experiencing something.
"Are you in a dark place in your personal life and it helps make the movie? Or do you put yourself in that place in order to make the movie?"
And the hunk - who is nominated for the Best Actor Oscar for his role in film - admits he couldn't help but take the "moods" of his character home with him.
He said: "I did hold on to his moods, his personality, because once I'm in it, I have to stay there as much as I can.
"I'm not an actor who can move in and out with ease, it's too hard to go back there and take on that weight again.
"Did that make me fun to be around? Probably not."
137 min | Drama
After Lee's older brother Joe (Kyle Chandler) suddenly passes away, he is made the legal guardian of his nephew. Lee is forced to deal with a tragic past that separated him from his wife Randi and the community where he was born and raised. ...get tickets watch trailer