Narcissists and Projection
It's a very common occurrence in narcissistic relationships, and it makes up a huge bulk of the reason why they do certain things. So what is it? Projection is when the narcissist takes something of their own - like a feeling or a behavior or a trait - and projects or puts it onto another person. The best example of this is when the narcissist is continuously accusing you of hating them. You have no idea why, because you don't hate them and your behavior certainly wouldn't be coming across that way to anyone else, so where are they getting that idea? The answer is projection.
Narcissists have serious emotional problems, to put it lightly. Despite what many think, narcissists do have emotions, and their emotions are often very strong - even overwhelming. Many narcissists don't consciously acknowledge their emotions at all, yet these emotions exist, and they control every aspect of the narcissist's life and color their perception of everything. To the narcissist, feelings are facts. This creates a convoluted internal landscape, especially for those that are in denial of their emotions in general. They can feel these emotions, but because they deny and refuse to acknowledge them, they often experience them as happening externally, meaning coming from somewhere outside of themselves. They can feel the hatred but because they are in such denial, they cannot acknowledge that it is self-hatred. This is too hurtful to acknowledge and too hard to defend against. So they assign the feeling to someone else. "I don't feel this way. You do!" In this way, they keep these hurtful feelings at bay and preserve the fragile fiction that their entire existence is predicated on. Their entire life revolves around maintaining that false self and the idea attached to it, that they are not the horrible pieces of garbage they secretly believe themselves to be.
Without that false self and the sustenance they receive from it through other people, they have no ability to regulate their emotions or validate their self worth, so they will go into a downward spiral that ends with decompensation, dissociation and sometimes even psychosis or suicide. They literally fall apart without it, and narcissists that do not have an extended network of those they can feed off of are perfect examples of this. They are often low-functioning, depressive and prone to suicidal or otherwise self-harming types of behavior.
The overwhelming majority of narcissists were themselves victims of childhood narcissistic abuse, so they end up with the same idea that all victims of narcissistic abuse end up with: that simply being a normal human being is somehow wrong. Basic human flaws and normal limitations of ability are considered inexcusable failures by the narcissist, both in themselves and in other people. Virtually all of their projection and the behaviors related to it are centered around this one thing: the narcissist's delusional, childish idea of what a "good person" is and the illusion they are trying to create that they are one. Good people don't hate themselves. Good people aren't abusive. Good people never make mistakes or have accidents. Good people are perfect. Good people are never at fault for anything. Good people are always right. Anything they do or feel that does not fit into this idealized, emotional definition is projected on to other people so that the narcissist can deny it is a part of themselves. "I didn't do that bad thing. You did. I don't feel that bad way. You do." Projection is able to alleviate some of their distress, but not all of it. They are never able to be perfect, so they walk around feeling shame and self-hatred all the time.
Pathologically narcissistic people, like most victims of narcissistic abuse, carry a permanent sense of failure with them always. They have been taught that they are not good enough and never will be. In defense against that and the horrible self-hatred and shame it provokes, they've created a pretend self that they think meets these expectations. Of course, nothing can meet those expectations because they are totally unreasonable. Everyone has flaws. Everyone makes mistakes. To the narcissist, this is completely unacceptable - even if it's something very minor. It's more than unacceptable. It's evil and wrong, and means they are, too. So they blame. They gaslight. They project. "I didn't fail. You failed! You forced me to fail! You sabotaged me! You're blaming me! You're just saying that because you hate me!" and on and on and on. What they are really saying is, "I cannot take the shame of this failure. You take it." Now, you would think in the case of minor mistakes, it would help if you said, "I understand that you feel shame over this mistake or this thing you did wrong, but it's not that big of a deal." But it usually does not. They are utterly convinced of this programming, and letting them know you see their secret shame and vulnerability often makes things worse, not better. They will not believe you anyway. To them, it is a big deal. It's a monument to their ultimate failure and eternal incompetence as a person, which is the secret they are spending all of their energy trying to hide.
You can see evidence of this when they are forced to acknowledge a mistake or to take responsibility for something they've done. Instead of just a normal dispute or conversation, it becomes a sweeping indictment of their self-worth. Suddenly, the conversation is about how you believe they are a terrible person and subhuman because they did not call the gas company or because they left muddy footprints on the clean kitchen floor. And you're like, "Whoa. I'm not saying that at all" but it's too late. Pointing out a mistake they've made, something they've done wrong or a flaw in the narcissist is the ultimate betrayal, in their eyes. You've unwittingly exposed that disgusting, defective thing they are trying to hide and they will never forgive you for it. They perceive this exposure as a blatant attack, a threat on their very life and they will fight back with everything they've got against it. This is often one of the first serious indicators people get that someone might be a narcissist: the inability to understand having flaws or making mistakes is OK, and the disproportionate rage that happens when these things are pointed out.
In the end, the biggest difference between those who end up pathologically narcissistic and those who do not is probably that for whatever reason, narcissists are unable to mature and move on. Those who do not end up narcissistic are able to accept, regulate and control their emotions. They do not need to resort to projection, blame-shifting and gaslighting because they are in such deep denial of their own feelings. They know what a good person is - and what it isn't. They know that it's OK to be human. Sadly, for the narcissist, this is not something they will ever know or be able to accept.