Narcissists hope for love and caring, but feel very uncomfortable if they seem to find it. Being in love makes them feel vulnerable and this terrifies them. They doubt the authenticity of real love and devalue anyone who loves them because they believe that person, like themselves, can never live up to their expectations of perfection.
Narcissists cannot grasp the concept of unconditional love that includes the acceptance of flaws. Love does not sustain them. Instead it feels unsafe. Admiration feels safer because it can be earned through achievements and credentials. Since these are things the narcissist can control, they feel much safer being admired, rather than loved.
As a result, narcissists seek attention and admiration from anyone who will bestow it. Those who profess their love are eventually discarded and devalued. For this reason, trying to love a narcissist is a maddening and precarious way to live. It can drive anyone to the edge of their sanity. Narcissists are completely unaware that they vacillate between idealizing and devaluing others and would rather be admired by many than loved by one.