Denial is at the core of narcissism. Without it, Narcissistic Personality Disorder simply could not exist.
“Denial (also called abnegation) is a defense mechanism…in which a person is faced with a fact that is too uncomfortable to accept and rejects it instead, insisting that it is not true despite what may be overwhelming evidence.” Simply stated, denial is lying to yourself and believing the lie.
Brought down to its very essence, denial is expressed in two basic forms: lying to oneself about others (the woman who cannot admit her man is cheating on her, for example, even though there is ample evidence of his perfidy) or lying to oneself about one’s own self (the jowly, bloated, middle aged matron believing she looks “hot” in fashions better suited to her 13-year-old daughter). One need not be a narcissist to engage in denial—we all do it from time to time, whether it is in reference to romance or fashion or health. But while not all deniers are narcissists, all narcissists are deniers—narcissism could not exist without the ability to deny reality and believe that denial.