Think back to when you were in elementary school. What kind of person were you? Shy or outspoken? Active or reclusive? What were your interests and preferred activities? Do you recall your first experience with a computer? How did you feel about it?
If it’s too challenging to drudge up details from that far back, then think of middle school or high school. Ask yourself the same questions.
Now think of one of your favorite characters. Construct a childhood biography for him. Ask the same questions as far as elementary life, middle school life and high school life. You might even explore college or work.
How does this information influence your character’s current behavior? In what ways does he think, move, believe because of his past experiences?
Once you’ve gathered this information, go back into your story and reread. Considering the things that your character has seen and done over his lifetime, rewrite a few scenes that are changed because of your understanding of who this person is.
Have fun with this one.