The word narcissism in general means "self-worship." Consequently, unhealthy narcissism is a form of claiming too much for the self, whether we are taking resources from others, or indulging too much pride in our talents or achievements. Perhaps we have had fortunate circumstances in business, family position, beauty, or other inherent gifts from God or the natural world. While healthy narcissism does involve our ability to feel proud of special accomplishments and to take pleasure in our abilities, we generally know that heady feeling when we indulge in undue pride, a tendency that leads to self aggrandizement. The moment we claim more credit for ourselves than we deserve, we participate in the illusion of "special ownership" or "entitlement" and head towards the dead-end of toxic narcissism.
-- Eleanor D. Payson, The Wizard of Oz and Other Narcissists, p. 166