I'm so Lost

So who saw the season finale of Lost? I am hopelessly obsessed with this show and I have been since it started. I have been known to have hour-long conversations with family members (while Rand rolls his eyes) and friends about the theme and meaning of this show. I frequent "Lostpedia" far more often than I care to admit. And I don't know why I do this, because I am still no closer to understanding what is going on. So if anybody has any theories, let me know. Why do they have to go back to the island? How did Locke get off the island? What happened to the people left behind? Where is Claire? Why do I care? Why don't I get a life?