You’ve heard it before: “Crazy is what crazy does.” True. Forrest Gump was a lot brighter than people gave him credit for. It’s also true that film is a visual medium. Action does speak louder than words; it’s what a character does that reveals the most to the viewer.
But there is dialogue. Your characters do speak. And although the screenwriter should take every opportunity to “Show! Not Tell”, even the most seasoned movie writer will find it necessary at times to incorporate exposition – almost always used to provide background information in order to help the audience understand an essential element of plot, character, or the world of the story.
Almost every movie has it, but not every film does it well.
There are some tricks of the exposition trade you can apply. One of the easiest ways to have a character deliver believable exposition is by giving that character an occupation: a lawyer, a teacher, a coach, a doctor, a cop, a scientist, etc. If your character is an expert in a particular field or has a niche specialty, and it’s also part of his or her job description to lecture or orate, exposition usually works quite well. However, what often happens is that these characters become stock or stereotype roles: “Oh, here comes the guy in the lab coat. Pay attention. Prepare for an information dump.”
So even though applying the right occupation can help, it still comes down to character. Why is your character interesting? If it’s just because he or she is wearing a lab coat or a uniform, you better take a deeper look and try again. But if your character is a schizophrenic scientist or a psychotic lawman, now you have something that’s memorable.
Truth really is stranger than fiction, and we tend to believe the interesting crazy person more than just a guy wearing a lab coat. There’s a big difference between the memorable and eccentric Dr. Emmett Brown (Christopher Lloyd) explaining how the DeLorean time machine works in Back to the Future vs. the forgettable cookie-cutter science guy that tells us the world is going to end because of blah, blah, blah.
I say choose the unstable, unpredictable, nervous, paranoid, and a little bit crazy character every time.