Narcissistic personality disorder
Before the introduction of narcissistic personality disorder, the term narcissism was used to explain a person's extreme self-love and self-admiration. The word narcissism comes from Greek mythology. A handsome young man named Narcissus saw his own reflection in a pool of water and fell in love with himself. Narcissus' love could not be returned back and therefore he became a flower, which was named after him.