More of the way I percieved it:

The opening shots of him on the phone. He was happy. He was making other people laugh, and it was making other people happy. I doubt he got into comedy for the fame. But you saw how he was deriding his fans - smiling, only to make fun of them, pick them up to fuck them, that kind of thing. His life was empty, without joy. I gathered that he slowly turned into a materialistic asshole who surrounded himself with shit he thought was important but didn't even really notice - his frustration at not being able to watch the hockey game on his own TV was very telling that he never really had an appreciation for anything.

At the end of the movie, he turned into the complete opposite. The three minute scene at the mall, when he starts writing jokes for Ira, completely reverses the strange relationship they had - it was a gesture of not only friendship, but respect. George started laughing at Ira's jokes, and for once, looked for a way to improve someone else's life rather than his own. That one scene conveyed so much about how George had changed. I was very impressed that such a short ending to a long movie could have the impact that it did, but it showed such extreme growth on his behalf, and even moved him into, dare I say it, happy territory? He looked fucking ecstatic to be helping Ira out. He souded tired, but he looked happy.

He almost lost his life, but he never really had much of one to begin with. He tried to take someone else's to make him happy, and when that failed, he blew up at the only friend he had.

I dunno, I really liked it.