I've cut and pasted my reply below from another thread, rather than attempt to derail that one. So anyway :-
I think that npd is unlike any other disorder, in that unaware narcissists deceive themselves to such a great extent. I find that degree of self denial remarkable, yet it's only occasionally mentioned, almost in passing. To me, that self deception should be up there with a lack of empathy, as one of narcissism's defining features, yet it doesn't appear on any of those lists of criteria.
The idea that we can be oblivious to our actual selves for much of our lives (to such an extent) is very interesting to me. I mean no disrespect to fellow narcissists, by the way, in talking about self deception. My therapist told me that it was an unconscious defence mechanism, and that if I'd been aware of it, it wouldn't have worked.
Does anyone else find this aspect of narcissism as unusual as I do?
P.s., I did start a similar thread a while ago, but that one was related specifically to unacknowledged hostility.