Credit: Jeffrey Mayer/WireImage

Heath Ledger’s death in 2008 sent shockwaves through many in the Hollywood community, including Jake Gyllenhaal. The actor starred opposite Ledger in the 2005 film Brokeback Mountain, and says Ledger’s death impacted both his personal and professional life.

“Personally, it affected me in ways I can’t necessarily put in words or even would want to talk about publicly,” Gyllenhaal, 35, told PEOPLE and EW editorial director Jess Cagle about Ledger’s death during the latest edition of The Jess Cagle Interview. “In terms of professionally, I think I was at an age where mortality was not always clear to me.”

Gyllenhaal had just turned 27 when Ledger died from accidental prescription drug intoxication, and says he had not lost a lot of friends up until that point.

“I think you live in this bubble, too, of making films … there are real friends, and there is a real community,” he said of the experience. “There is also that [new Macklemore song] where he says, ‘The curtain closes and nobody notices’… I think that’s true, and I think that’s okay. But I think at the time, I assumed everyone would notice — and they did with Heath dying, but I think it [gave me] the experience of, ‘This is fleeting.’ And none of the attention or synthesized love that comes from the success of a film really matters at all. What matters is the relationships you make when you make a film, and the people you learn from when you’re preparing for a film. That changed a lot for me.”

Brokeback Mountain served as a breakout moment for both Gyllenhaal and Ledger — each actor scored his first Oscar nomination for the film, and Ledger would begin a romantic relationship with costar Michelle Williams during its production.

“We were super young,” Gyllenhaal said of making Brokeback Mountain, which also featured Anne Hathaway in a supporting role. “We had no idea what the movie was going to become.”

Watch Gyllenhaal open up about making Brokeback Mountain and how he coped with Ledger’s death in the video above, and check out his full interview with Jess Cagle below.

Gyllenhaal will next be seen in Demoltion, a new film from Jean-Marc Vallée (Wild) about a man struggling in the aftermath of his wife’s death. Demoltion is out in theaters on Friday.

Brokeback Mountain
  • Movie
  • 134 minutes