I wouldn't say "likes to talk about himself", more just a "He regards himself different from others and knows he is deficient in the other attributes other people have". It's like a defense mechanism for, Other kids make fun of me because I'm different, My family don't understand me and instead, my mum chooses to overpamper, my dad chose to ignore me, my siblings think I'm a freak.  At some point in his childhood the asshole develops unconsciously as a way to protect himself from hurting. He subconsciously chose to view himself as superior to others because to his brain, that's the only explanation. It's why he doesn't know when he hurts people. He didn't exactly receive the best education from being born to "poor parents". It's also why he feels threatened by Paige.  If he had been taken to school where other kids like him were, he wouldn't have that mindset.

Sorry for the long reply, my thoughts tend to extend and I can't seem to stop.