Narcissists get “stuck” at the egocentric stage of emotional, psychological, and spiritual development. And their self-absorption keeps them from paying attention to and learning from what only caring, intimate relations with others can teach them.
It’s not enough to simply think before acting. What you think and how you’re thinking matters, too. You have to think with social awareness. And your thinking has to be guided by sound principles. Disturbed characters operate on the pleasure principle and the self-serving principle. But healthy characters operate on the principle of the greater good.