A narcissist feeds off of other people. By 'accepting' this, and living around them, you sacrifice your life and personal sanity to their disorder. I am not at all an advocate of that. All of the narcissists that I have ever met have this have a false, over inflated idea of themselves, and tend to punish anyone who threatens that. By changing your behavior, you are not only reinforcing their delusions, but validating their behavior.