In movies, there are no victims or innocents. Everybody does things
because of some motivation and you have to show us what these things
are. All important characters do things because of past events. The more
clearly you show what these past events are, the better the audience
understands the story and the implications at the end of the film.
If you don't show us why the character behaves the way he or she does, we
lose interest in the story. Why? Because the actions then become a
cliché, something audiences and critics terribly dislike. A cliché
is something that means something else, everybody recognizes it and
understands its meaning. It is very general, overly familiar and moved
from personal experience.
When you prove to us the character had to act the way he or she acted, the story
becomes more specific. Specific behaviors are the total opposite of a cliché.
Also, when audiences understand motivations, they naturally become
interested in the film. The events cause audiences to recall their
own experiences. The story becomes personal in other words.
To summarize, prove to us each event had to happen, and you will help us
maintain interest in your story.
Based on Eran Preis, Scripting for the Media I - Writing From Life (Temple University).