Before you start production, you have characters you have created without actors in mind, then all of a sudden you've got actors. They bring an enormous amount in creating these characters, and creating the dynamics between the characters that you've written.
“In marriage there are no manners to keep up, and beneath the wildest accusations no real criticism. Each is familiar with that ancient child in the other who may erupt again. We are not ridiculous to ourselves. We are ageless. That is the luxury of the wedding ring.”