Ugh, mixed emotions. In my opinion, just because you know stuff about someone, doesn't mean you care about them. I know tons of people that i hate, but i still know stuff about them. And with Michael, it's sort of the opposite, he used to care about them, despite not getting to know everybody, but since the start of the hunt for the zombies, he has been too absorbed by it, making it his one priority, or at least that's what we've been shown.