That's not so ironic as it seems. Many people get their first experience of NPD because they are raised by narcissistic parents, and it takes them half a lifetime to figure out what is really going on, and then another half a life-time to learn that they are not alone. They have been conditioned for years that their own observations and conclusions are wrong, and most outsiders simply won't believe them when they try to explain their parents are not the wonderful people they project themselves to be. So victims of narcissists tend keep their thoughts for themselves, as they are in constant doubt about their validity.

One of the primary tactics of narcissists is to isolate their victims, because they constantly need to manage their victims' self-image. Victims of narcissists are typically unaware that the relation they have with the narcissist is not "normal", and because they are isolated, they hardly seek or receive external feedback.