Talking with a Narcissist
I can't be sure of this, but I've found it in two narcississts I knew well: They were terrible at recognizing faces and remembering names. Embarrasingly bad. But both were good at hiding it, so you had to know them well and get lucky to catch them unable to fake it often enough to realize this about them.
The impression I got from both these people is that their mind was going a-mile-a-minute while interracting with you, that they couldn't pay attention to what you were saying because they were too busy thinking of what they were going to say next. Then they'd blurt it before you were even finished, as though unaware that you were in the middle of a sentence. Needless to say, they were always getting what you said screwed up.
This makes sense if you remember that you are just a mirror they're posing before in an interraction. They aren't interested in you or anything you have to say. They are interested only in the image of themselves being reflected by your behavior. You yourself -- your face, your voice, what you say -- gets filtered out like the picture on the wall behind you or background noise out on the street.
If they meet you again tommorrow, they won't recognize you, let alone remember your name. That's how self-absorbed they are.