I've been thinking about this - Pat uses Social Media the way a very vain and shallow woman stereotypically does. Posting lots of pictures of his stupid face, narrating meaninglessly trivial aspects of his life as if they were really important, boasting about his belief that he's sexually attractive and all the sex he has, dispensing air-headed advice on subjects he knows nothing about. It's quite unusual for guys to use Social Media in that way, at least straight ones anyway.
Thing is, the women who post like that do it because they get constant asspats in the comments from simps or friends who want to blow smoke up their asses (You go girl!), which gives them huge egos and feeds their belief that everything they do is terribly important, that their inane musings are pearls of profound wisdom, and that they're stunningly attractive. Pat, so far as I can see, gets no feedback at all when he posts about his life or posts pictures of himself, and very little support for his opinions. The fact that he can keep up this narcissism in the face of absolute silence (and consistent mockery here and elsewhere) really shows that it's more of a psychosis than learned behaviour. He's responding without the stimulus. Add that to his obsessive need to get the last word and respond to every single criticism, and you have a picture of a man whose life is totally controlled by obsessive and compulsive thoughts and behaviour, Lucas Werner style. The Wern also thinks he's the smartest, most attractive guy in the room despite overwhelming evidence to the contrary. He is also in complete denial about the disaster his life has become, much like Pat. And like the Wern, he talks big but does very little - Pat's too chickenshit to ever follow through on his tough guy threats of violence towards people, and the Wern is too scared to actually approach women and talk to them despite the desire for a partner taking up every minute of his time and thoughts.
A psychologist could probably write a PhD thesis unpicking the inner workings of Pat's brain. Dude is broken in a really unique way.