Narcissism Revealed

Basically, an adult Narcissist is just a person who grew up but did not go through what others go through as far as learning how to interact with others, and why. Either for external or internal reasons, or both, a person with Narcissism did not learn WHY it is better for everyone if we behave a certain way, or do certain things, or have AWARENESS. They may never even have been shown or taught that there is Life outside their personal realm at all.
We have all known children who did not treat others with respect, or manners; who wanted what they wanted, no matter what, and would throw a fit if they didn't get it. Children who did not say "thank you" when given gifts, and who did not say "Please" when asking for something, or who didn't even ask at all, as if others were paid help.
Many of us forget that the reason we learned these lessons is because we were TAUGHT, purposely, and usually by more than by just one parent.
All of the people around us teach us by example, constantly.
If we are surrounded by negative, controlling, pessimistic, scarcity minded, narcissistic or abusive people, then that is the mindset we learn to have, even if we fight it. Even if we can see it while we're growing up, it still makes a huge mark on the way we see the world; it forges lenses for us to see our selves, our lives, and our worlds through. If no one teaches us how or why to NOT be Narcissistic, then there's a good chance we will become that way too, and not even know why, or that we are.
Basically Narcissism can be seen as a kind of internalized childishness, a lack of awareness that one did not go through certain growth and learning stages. Like a permanent 6th or 7th grader who has not learned about humility yet, who seeks all the rewards of adulthood without understanding anything about adulthood. It's really more like a disability, and renders the sufferer very much alone inside, without knowing why.