Can't Handle The Truth: Expectations, Disappointment, And Narcissism

When something or someone does not align with their expectations, people are often either surprised or disappointed, but get over their emotional reaction pretty quickly because they have awareness about their own expectations and preferences being their OWN, coming from themselves. They know that if their expectations and assumptions weren't met, that THEY were simply incorrect, that they thought "wrong", that they assumed incorrectly.
For example one walks into a restaurant that looked like a "dive", a cheap place to get a mediocre pizza, and finds out that it's actually a great restaurant with a wonderful menu, excellent prices, and fantastic food. A person with healthy self-awareness would be surprised that their assumptions about the restaurant were "off", but they would not "BLAME" the RESTAURANT for the "discrepancy", they would simply think "Oh, not what I thought!"

Or when one person meets another person, we tend to assess and assume WAY too much about others with way too little information, but we're aware of that human tendency, and we know we're going to find out more and different things about a person than we had pigeonholed them as, every single time. So we don't take our assumptions too seriously; we wait and see what a person is really like, and we simply go "Oh I was wrong about that" to ourselves when we find out more about them.

Narcissists, on the other hand, have a very hard time with UNMATCHED expectations and assumptions.

A person with Narcissism really seeks control over his or her environment in order to feel either safe, or safe to "walk over" other people, depending on the individual N. So they make very large assumptions about other people, places, situations, future events, and objects, and EXPECT those assumptions to be correct. When those assumptions turn out to be incorrect, the N. can become very upset, agitated, even go into a rage. OR, the N. will simply IGNORE the discrepancies and differences between their assumption and reality, and just keep behaving as if everything they had assumed was true.

To put it bluntly; if a Narcissist meets a person and they assume the person is stupid, ignorant, or inexperienced because of the way they look, the Narcissist will most likely keep treating the person according to their original assessment even after it comes to light that the person won a Nobel Prize, or has a super-high IQ, or is an expert in the field that the Narcissist assumed them to be inexperienced in.
AND/OR, the N. will decide to DISLIKE the person, even despise them, literally because they didn't LINE UP with the expectations and assumptions of the N.

Because, it's a Narcissistic Injury.

That person was "supposed to be" STUPID (or lazy, irresponsible, unstable), and so when they turn out NOT to be stupid (or lazy, irresponsible or unstable), they are insulting the N's ego.

They made the Narcissist BE WRONG.