The Stronger star covers the latest issue of GQ Australia, where in addition to talking about his new film, surrounding the 2013 Boston Marathon bombing, the 37-year-old actor reveals how he and the late Dark Knight star came to know of each other before sharing the screen in Brokeback Mountain in 2005.
“I was auditioning for Moulin Rouge! -- Baz Luhrmann had chosen three actors. It was Ewan [McGregor], it was Heath, and me," Gyllenhaal tells the publication. "And we auditioned with many different actresses, it was a long process. But I never met Heath, I only heard about him. We would be shuffled in and out of rooms. They would literally put me in a room and lock the door and Heath would come in and then Heath would be shuffled through the door. I never saw him."
The role ultimately went to McGregor, after which point Gyllenhaal says he and Ledger became friends out of "mutual frustration."
“When Brokeback Mountain came out and it got all the attention it did, I remember, a few months later, Heath called me and he was like, ‘Hey mate, I got some news for you.' I said, ‘What?’" he recalls. "He said, ‘Baz just offered me his next movie. I just wanted you to know, I f**king turned it down!’ [Laughs heartily] So that was how much Heath loved me, you know. That was how I met him.”
Both actors were nominated for Brokeback Mountain at the 2006 Oscars, and the film would go on to win three awards. Nearly two years later, in January 2008, Ledger died of an accidental prescription drug overdose at age 28. He went on to win a posthumous Oscar for playing the Joker in The Dark Knight in 2009.
Meanwhile, Gyllenhaal plays Jeff Bauman in his most recent film, a man who lost both of his legs in the bombing. The actor says that he hopes the film conveys the story of the people affected by the tragic event, rather than the attack itself.
"I remember I was in New York and I remember seeing the photograph of Jeff,” Gyllenhaal recalls. “I remember being affected emotionally by the situation… what is less interesting to me is the sensationalizing of the people that commit a crime, and the crime itself, as opposed to the people that are affected by it.”
Elsewhere in the interview, Gyllenhaal comments on the moment in Hollywood leading to the Time's Up movement, admitting even with family in the industry -- sister Maggie Gyllenhaal and his screenwriter-director mother Naomi Foner Gyllenhaal -- he wasn't aware of the extent of the harassment problem.
“Not in this way. Not in a predatory way," he says of how aware he was before all of the stories started coming out. "I’ve been very aware, also because I have a sister and a mother in the business, of misogyny, but not like this in any way.”
In July of last year, ET spoke to Stronger director David Gordon Green, who explained why Gyllenhaal is the only person who could star in the film.
"He's actually the only actor I spoke to about it. There's a seriousness that you can tell he has within every character, but I've always really responded to the sly goofiness he has as well," he shared. "You can see it even in his most serious roles."
And watch the video below for what Gyllenhaal told ET on why Stronger changed his life.