Apparently it's because he's more special than the rest of us and he doesn't have to follow rules because he's Captain Jack Harkness. [There's a lot of bitterness in his voice, especially since that's what all his reasons seem to boil down to. He used to understand it, but he stopped trying years ago.]
I lost control when we were arguing this morning. Just for a moment. But I've never done that before. [Much more subdued, like he's ashamed to admit it. Losing control means a lot more now that he's not human anymore.]