The first reason should be almost intuitive:
1. No matter whether your story is inspired by a character, a world, or a plot (all are valid starting points), it's the character who fuels the emotional dimension of the story, who causes your readers to identify with and hook into your tale.Some people start writing a story because a certain character grips their imagination; some people naturally create worlds and wonder what kinds of adventures might happen in them; and still others have an idea for an adventure and set about creating characters and worlds in which it might take place. There is no single right way to develop a story idea but, when all is said and done, it’s the characters in the successful story that the reader ultimately remembers.
This should come as no surprise. No matter how novel the world is or how gripping the plot, we are “characters” ourselves and so we tend to identify with other characters whom we find appealing. For that reason alone, we owe it to our readers -- and especially our youngest readers, who may struggle with the very act of reading -- to make our characters as “identifiable with” as we can...
And what readers generally identify with is a character who wants things that they can sympathize with.
Think about that for a minute. Think about the stories (or series of stories) you’ve enjoyed most. Isn’t it the characters — or frequently, one particular character — that you most relate to? Or think about TV and movie series that have developed huge, almost cult followings. Don’t the fans usually identify with one specific cast member’s character? (If you see them at a fan convention, you probably don’t even have to ask which character that is; you can recognize the character’s costume, which they are most certainly wearing. Beam me up, Scotty!)
Knowing that readers tend to identify with characters who share the same passions as they have, doesn’t it make sense that the most important thing to know about a character is what he or she is most passionate about? Any time you find yourself stuck and unable to decide what a character should do in the scene you’re writing, you should immediately stop and ask yourself:
What is this character most passionate about? What does he want most, and what is the most logical choice he could make at this point in this story to bring him closer to that goal?Nine times out of 10, I bet the answer to those questions will get you unstuck.
There is no more important thing that you can know about a character than their heart’s desire. This one piece of information serves as the character’s compass... and yours as well.