^Well, he gave that impression of being very confident but I think that he really wasn't. He was always full of worries, at some point it seemed like he was paranoid, he thought that everyone was really against him even though he tried his best to make people like him. He was relatively smart but it seems like sometimes he tried to come off as smarter and more confident than he really was. He created his image that way but I think that it was far from his true personality.
However from that part when he said that he has no friends, only supporters and people who are against him I thought that things that he said were more and more depressing. He didn't look confident yet he tried to speak like he was very confident, hard to describe I guess.
I think that's where his 'aggression' came from. It was there to hide his weaknesses and show that he's "not to fuck with". Looks like he was trying very hard to achieve that.