When you read these individual descriptions of how what is considered a "narcissist" failing to give you the love and validation YOU need, what these different ways these individuals treat others means is "they are unable to give something they do not know HOW to give". These individuals were never "taught" how to give you what you deserve. If you allow yourself to decide that it's "intentional" behavior then you are only going to be hurt even more, and I know how very hard that can be. Your disbelief is because you have made it a point to "learn" and in that when the behavior is exhibited towards you, you will say "I can't believe how bad this behavior is".