Recently, I listened to a lecture on writing. The speaker was talking about creating characters. He made an interesting point I’d never considered. An obvious point. It is that, unlike real people, you as the writer know all about your character, his background, his likes and dislikes, his loves, his little quirks, and, more importantly, his inner thoughts.
Of that list of characteristics, the only one that none of us can really know about actual people is their inner thoughts. In intimate relationships we may ask another what they’re thinking, and we trust them to tell us, but we really don’t know if they tell us the truth.
Now, I’m not trying to raise suspicions about your significant other. My point is that, by knowing the thoughts and motivations of your characters, you have a significant advantage over the real world in your fictional world. This gives you the leeway to mold your character anyway you want.
You’ve heard the expression “to get inside his head”. That’s what you’re doing when you write about one of your fictional characters. The good thing about that is you control what’s in their head. After all, they are not real people, and for that matter they don’t even have to be people. Some classic novels such as White Fang by Jack London, Watership Down by Richard Adams and Animal Farm by George Orwell all have animal protagonists. Then there are a host of vampire novels with humanoid heroes who definitely are plagued by atypical problems (living forever, exsanguinating people in order to survive, etc.). And of course in the fantasy genre you deal with elves, dwarves, orcs, and more. My point is it doesn’t matter who your protagonist is, you have the power to decide their likes, dislikes, dreams, aspirations, and loves.
As you explore and write about your main characters you have to know all about them. But, you have the option to reveal to your reader as much or as little about them that you want. The only caveat is you must master your character’s mind, that is, know them as fully formed entities before you decide how much or how little to reveal about them.
I’m reminded of a scene from the movie Patton starring George C. Scott. In it General Patton has ordered his soldiers to attack the enemy and he emphatically yells, “If we are not victorious, let no one come back alive.” At that point his aide whispers to him that sometimes his men can’t tell when he’s acting and when he’s not. Patton retorts with, “It’s not important for them to know, It’s only important for me to know.”
You are your novel’s General Patton. It’s not important that your readers know all about your characters, it's only important for you to know. So, write about your characters with a general’s authority. If you have complete knowledge of who they are, you’ll be confident enough to reveal just what’s important for your readers to know.