The dictionary defines narcissism as “excessive or erotic interest in one’s self and one’s physical appearance.” At best, it’s a trait that others find downright aggravating. At its worst, however, narcissism can be a pervasive, destructive personality disorder. In her new book, Everyday Narcissism: Yours, Mine, and Ours , psychologist and social worker Nancy Van Dyken peers beneath the egotistical veneer to explain the roots of narcissism and how to get past it. The book draws a distinction between the clinical personality disorder and what Van Dyken calls “everyday narcissism.” She defines the latter as “a garden variety form of narcissism that we will recognize through people who are prone to pleasing, trying to get other people to please them or take care of them. It’s an unconscious level of wanting to be taken care of and feeling responsible for other people.” In her book, Van Dyken writes: “Carrying the well-being of others on your shoulders? Heavy, isn’t it?…