As chronicled in the best-seller by Jon Krakauer, Into the Wild, Christopher McCandless excommunicated himself from friends and family in 1990 and embarked on a cross-country journey. By 1992, he had made his way to the Alaskan wilderness, where he died during the punishing winter at the age of 24. Some consider him an inspiration, others a fool, while director Sean Penn wisely leaves room for both viewpoints in his film (though he clearly leans towards the former), which opened September 21 and continues expanding nationwide this Friday.

After starting as a child actor in TV shows, Emile Hirsch has gone on to surprisingly mature roles in films like Alpha Dog and The Mudge Boy, with only occasional detours into teen territory (The Girl Next Door). Now, Hirsch is receiving near-universal acclaim for his approach to the complex role of McCandless. We spoke with Hirsch at a roundtable in Toronto, touching base on youth and rebellion, losing weight, and his upcoming starring role in Speed Racer.

(An interview with William Hurt, who play's Hirsch's father, follows on the second page.)

Was this story particularly resonant at your age?

Emile Hirsch: I think it was really relevant in my life. I can't speak for every young person. It was one of those things that I went into and it wasn't like I looked at it from an older person's perspective, like "Oh, this is that point in your life." I looked at it as a very in the moment kind of thing, and I was really excited to go on the adventure of it. Maybe something when I'm older I'll look back and really be able to evaluate what was going on. But for me it was more of the, "Yeah, rock and roll!"

Do you think that you'll feel differently about the character than you do now in the future? Or do you see flaws in his character now from your perspective?

EM: I would probably not be comfortable not talking to my parents and my family. But that was something that he did. And that is something that I probably wouldn't do.

What do you think Christopher McCandless would think of this film?

EM: I think he'd be pretty excited about it and the effect it could have on people in a positive way. He [was] a person of action who wanted change. He's a person who studied humanitarian things. Even in high school, he was so concerned with Apartheid. Anything that he thinks can help change the bigger picture, I think he would think is a good thing. And his sister Carine has verified that.

I can't speak for what I think it will do for everybody, but just for me, it was a very inspiring story for me in my own life. That's the only gauge that I can have. Just living life to the fullest and the message [that] happiness is only real when you can share it with someone else. [Chris's] own epiphany that he was looking for was right under his nose. It was a sign posted throughout the journey and his travels, the people he met along the way. And it took him to be isolated and in the middle of nowhere to realize it.

Can you talk about your casting process? It sounds like there was a little back and fourth with you and Sean Penn.

EM: Sean had seen Lords of Dogtown. The director, Catherine Hardwicke, had actually screened it for him up in San Francisco in the hopes of getting him involved in a project that she was going to do at the time. He had just got the rights for Into The Wild, and he was on the lookout for an actor for it. So, he responded to the performance, or parts of it. And he called me directly on my cellphone. He was like, "Hey." I was like, "Whoa."

We got together and he was really vague. He was like, "I've got all these projects," like multiple things he didn't want to commit [to]. But he knew the whole time that it was really just this one thing. He told me to read the book and I read the book that night and was just floored by it and loved it and called him and told him that. Then over the period of four-and-a-half months, every three weeks or month he would call me and we'd go out to dinner or go drinking or something. At that point we stopped talking about the movie, and I thought that Sean thought I was cool and just wanted to hang out.

Then all of a sudden he called me and said he had completed the draft of Into The Wild. I guess though our meetings and hanging out, he decided that I was right for the part and he wanted me to do it. It was a really amazing kind of feeling for me for that to happen. It immediately started what would become a long physical process.

So you lost the weight before the movie?

EM: I weighed about 156 pounds when I got the part, and I weighed 130 pounds throughout most of the film. So I lost the 26 pounds to get in shape for the film. And then I went down to 115 pounds for the weight loss in the Alaska segment. So it was a lot of running and being very hungry and dreaming of candy all the time.

Did you visit the actual location where the bus was in Alaska?

EM: I did. I took a snowmobile ride out with this guy named BJ. It was a 90-minute snowmobile ride out to the bus, and the bus is still there. The boots are still there. And now there is all this writing on the bus from all the people who have visited the bus and written little notes. It's great because it's all so positive and no one goes all the way out there to bitch.

Did you write anything on the bus?

EM: Maybe...

How's Speed Racer coming along?

EM: It couldn't be more different that Into The Wild. Expect thrills, chills, and a heckuva good time!