Some of the best things I've learned have come from unexpected sources. Always be open to learning something from anyone.
I wasn't there for this, but it was related to me by a director who pitched a story idea to Michael Eisner. Eisner's reaction (In perfect David O. Selznick style) was "just tell me, what does he want and why can't he have it?" He was referring to the protagonist of the movie, of course.
A lot of screenwriting books will tell you the same thing - a movie is only as compelling as the goal that the hero seeks and the more obstacles in the hero's way, the more dramatic the movie becomes. Whenever I'm watching a movie and it starts to feel aimless and unfocused, I find that I've usually lost the thread of what the hero wants or why he can't have it.
The same thing goes for villians. What they want should be reasonable and, hopefully, be the exact opposite of what the hero wants. A villian who's just doing what he does to be evil is really uninteresting. A villian with a justified point of view is fascinating.
Scar in "Lion King" is a good example. He has a legitimate beef: he wants the throne and can't have it because he was born second instead of first. He thinks it's unfair, and resents his brother's air of superiority and dislikes his snotty nephew, and he feels like he is doing the justified thing for himself.
In the first "Spiderman" movie, I felt my interest waning towards the end because I had lost the thread of what the Green Goblin was up to. If I remember, his goal was to get revenge on some people, but it seemed like he did that at one point. But the movie kept going and he didn't have a new goal. It seemed like he was just bursting giant balloons and acting crazily because the movie needed him to...not very compelling.
Someone smarter than me said "Give your character a REAL physical goal based on a REAL emotional need". Too true. So many movies and TV shows fail because what the hero wants doesn't seem compelling. They try to hang all of this drama on what he wants...and it just feels false. Or what he wants doesn't seem like a logical choice to fulfill his basic emotional need.
Sometimes the goal of the hero is consistent all the way through, like a "Die Hrd" movie - Bruce Willis wants to kill all the terrorists, and the movie isn't over until they're all dead. In many deeper movies, the goal of the hero changes. In "Toy Story", Woody wants to be Andy's favorite toy, to fulfill his emotional need to feel important and stave off his fear that he is being replaced and no longer important. Through the course of the story, he learns that what he really needs to do is let go of his obsessive need to be #1 and accept whatever his fate may be. To find happiness in being with Andy, whatever his status may be.
I've learned a lot from films that do this in an unconventional way. In "The Shawshank Redemption", Andy is put in prison in the first ten minutes. What is his want? He won't realize that he has a chance to prove his innocence until an hour into the movie. What is his goal until then? The fimmaker invented many subplots to give Andy a few small wants until we get to the bigger want later. He wants a rock hammer, he wants to build a chess set, he wants to build a better prison library, etc.
I think they wanted Andy to be stuck in jail for a long time so that they could explore the theme - that a man can't give into whatever prison he is in. That your soul has to remain free, however it can, regardless of where you are imprisoned. If he knew in the first ten minutes that he had a chance to prove his innocence, or had a chance to escape, then it becomes a different kind of movie. A search for justice, or an escape picture. That's a different movie.
This is just me speaking out of hot air - I don't know much about the movie other than having seen it. I've listened to a little bit of the commentary - not much - and the director doesn't really address this anyway, at least not in the beginning. Hell, I don't know, Maybe Morgan Freeman is really the hero, I'm not sure.
As they say, opinions are like assholes, everyone's got one and they usually stink. Give my opinion all of the credence that you paid for it.
The obstacles in the hero's way don't need to be monumental. Sometimes the more monumental the obstacles in the hero's way, the less emotional they become. The climax of Cinderella is just her locked in her room and the mice trying to set her free. When you think about it, even if she gets out tomorrow she can go to the castle and try on the glass slipper. They didn't try to create a "ticking clock" or make it so that this was her LAST chance ever to prove she was the girl at the ball, which a lot of screenwriting books would tell you you HAVE to do. But it works really well. It's simple, emotional and dramatic. look at old movies to learn a lot - they did stuff that people don't do anymore. People will tell you "that won't work". But people still line up around the block to buy "Cinderella" on DVD.
Look at movies that don't do this principle at all. What does Dustin Hoffman want in "The Graduate"?
No need to write back and tell me. All I'm trying to say is that if you want to be a filmmaker, these are the kind of things to ask yourself so the mystery of movie-making will become clear(er) to you. Don't EVER take what anyone says as gospel, especially the people that write screenwriting books or create blogs with weird names. I have my opinion, you have yours. Listen to what everyone else thinks and embrace what makes sense to you, and discard what you disagree with.
Even if it's Michael Eisner.