EXCLUSIVE: Jake Gyllenhaal Reveals the Hardest Part of Playing Boston Marathon Bombing Survivor in 'Stronger'

Jake Gyllenhaal took his latest role very seriously -- maybe even too seriously. 

The 36-year-old actor stars as Jeff Bauman, a Boston Marathon bombing survivor who lost both his legs, in Stronger, but told ET that the hardest part about playing Bauman was finding his "humor."

"I think just sometimes understanding his sense of humor in the midst of, like, pretty dark things, that was hard for me," Gyllenhaal revealed to ET's Cameron Mathison at the Toronto Film Festival last week. "Because I think I I sometimes take situations too seriously and I think his sense of humor, how crude it is in the face of situations where you never expect it." 

Stronger, based off of Bauman's memoir of the same name, forced Gyllenhaal to learn to understand Bauman's pain as he adjusted to his new life after the bombing, and the actor says channeling Bauman's struggles helped him learn about himself.

"Around the world, with all these [hurricanes] and then also just some of these horrible things that are happening, know that you can end up in an even better place than you began," he said. "In my moments of darkness, where you think you can't continue, you can and most likely you can get to an even better place than where you started." 

"That's what Jeff shows us, and it's an incredible story," Gyllenhaal added.

Stronger, also staring Tatiana Maslany, Miranda Richardson and Clancy Brown, hits theaters on Friday.