Quite sure.

I've been researching NPD for years. Narcissists are deeply invested in what other people think of them. The NPD's self-esteem is tied to others' admiration of and attention towards them, it's called Narcissistic Supply. They need others to at least appear to do what they cannot do for themselves: love themselves. It's typically a response to insufficient nurturing from one or both parents who are more often than not narcissists, themselves.

People who genuinely possess a strong, unshakable sense of self-esteem are not narcissistic, they are healthy. You can tell when you've reached this point when neither compliments nor insults affect you--they are both merely opinions of people on the outside looking in. Only you know who you really are.