Here's what I've learned in the past 30 days:
1 - As I moved up to #1, the scripts got better.
2 - Why did they get better? The characters became fuller, clearer.
3 - How do I define "clearer"?
We're dropping in on a character on a particular day in their lives. They have busy lives before & after this story.
If a "character is just a function of the plot" as Tom Hooper says, they are cardboard cutouts who exist just for the script.
4 - The plot follows the character, not the other way around.
ex. In Citizen Kane, we're following Kane. It doesn't matter that the story isn't in chronological order.
ex. In the Godfather, we're following Michael as he struggles. It doesn't matter who he's fighting. All we want to see is how he takes on the mantle of Don.
ex. In Casablanca, we're following Rick. Is he really going to leave Casablanca?
5 - Most people mention the plot when talking about scripts #20-30. Most people mention the characters when talking about #1-19.
WHAT I'VE LEARNED: This is the best thing I've done for myself as a writer.
It's easy to read scripts, but the real work is studying why they work.