I see it as a sense of false confidence based on their attempts to impress people knowing inside that they are basically ignorant and worthless. A type of false bravado to overcome their deserved lack of self worth.
We see this one differently. I read Comey’s tweets, which were accompanied by grandiose pics, which he sent as he was finishing up his book. He sounded like a clinical narcissist. You could see a particularly conceited 16 yo going through a phase in which he thought he was singularly sublime and lofty. When a grown man still feels that way, he’s mentality imbalanced.