Sometimes your readers see your characters clearer than you do.  How often have you gone to a critiquing group and had them ask you, “Why did your character do that?”  Your first response is the childlike, because ___.  To which they say, “Your character wouldn’t do that.”

     Baffled you stop and think, Huh?  I know my characters.  I know what they’d do.  But wait, what do these people see that I don’t?  Did I forget something?

     You know your character’s inner workings but have you read the story with the eye of reader?  You have revealed something to the readers.  Somehow, by the character’s thoughts, words, deeds, and emotions, you gave them something and you missed it.  However, you have a success because they feel that they know your character. 

     Quit writing for a day, do something else, then go back, print it out, and read what you have.  Don’t read it with your little editor, don’t read it as the writer, read it as a reader. 

     You may find the little quirk you gave the character that made your critique group tell you the character wouldn’t react the way you wrote it.  If you don’t, don’t worry about it.  What you wrote made them react by them reacting in the way they did it shows that your character came to life for them.  Use it.