We're never going to be the ultimate-insider look. You can do 50 insider looks at this Hollywood business, and the satire didn't intrigue me. I think others can do that.

I'm emotionally invested in every movie that I do, period, because you've got to make that commitment. You're spending a year, 18 months of your life doing it. I'm invested in all those kinds of pieces. Most of the films I've had in my career have never tested well. I got lucky that sometimes I got supported by studios - or, at least if not supported, tolerated.

If you test Iron Man and that audience doesn't respond well, you can be damn sure that there is something wrong with the movie that you have to address. Because they're expecting a certain amount of action, right? They want a hero. There are certain things that have to be compatible with the way the audience is thinking about it. If you take some other film, like No Country for Old Men, you can end up with all kinds of crazy reactions.

A lot of time mistakes are very interesting - you look for the behaviour that's not the one you expect.

I play around with human things, human relationships and that, and allow that kind of talk to work in that way, on that level.

We're never going to be the ultimate-insider look. You can do 50 insider looks at this Hollywood business, and the satire didn't intrigue me. I think others can do that.

I do know when you look at some ballplayer and all of a sudden he is the size of a truck something is wrong.