To me, as a director and an actor, that's the main thing. "What's the heart of this story? What's the humanity of this story? And if the movie doesn't have it, then why am I watching it?" Even if it's a silly comedy, like Superbad or Knocked Up - Judd Apatow, I love, because he's all about heart. The humor comes out of the humanity.

When I worked with Chevy Chase, Michael Ritchie would say, "Just ad lib and try to break me up. Just insult me. Anything." When we were doing his close-up, or when my back was to the camera, I would come up with jokes or quips or anything, to get a real reaction out of him. He was smart enough to know that was gold. So it was great fun working with him and Michael, and getting to see how the two worked together. I think Fletch and Clark Griswold were Chevy's two best roles. He's so incredibly talented and still vastly underused.

To me, as a director and an actor, that's the main thing. "What's the heart of this story? What's the humanity of this story? And if the movie doesn't have it, then why am I watching it?" Even if it's a silly comedy, like Superbad or Knocked Up - Judd Apatow, I love, because he's all about heart. The humor comes out of the humanity.

I learned a hell of a lot from my co-star, Kurt Russell. He's one of my closest friends and was one of my best teachers. He was the pro. He approached it like a baseball player. Acting is a contact sport to him.

The funny thing about The West Wing is - and I don't know what Aaron Sorkin says about it - but I'm convinced it was a comedy. It's a very intellectual and cerebral comedy, but it was SportsNight in the White House. It had an energy and a vitality and an intelligence and a passion that's rare. And it was extremely difficult to do, because they were so demanding about the dialogue.

I'd been working on more traditional movie sets and TV shows at Universal. All of a sudden, here we're on location in Animal House, and it's down and dirty and quick. It was the way the new commercial world was shooting; the way the indie world was shooting. These were lighter, faster cameras. It was a generational change.

As an actor and a director, I always let my actors go... assuming they have good ideas.