I agree. I've been interested in how the stories we consume, whether presented to us by ourselves or others, affect our personalities. Thank you for pointing me to Vonnegut.

One thing I feel is often overlooked in this conversation are our physical urges, specifically the ones motivating us to action that is different from what the 'character' we want to be would do. That adds noise to our personality, and widens the gap between what we are and what we want to be.