dr. zooeuss said:
The writers for the show have been saying that after the season three finale, we'd be aware of a huge shift in the parameters of the storyline... now that the season three finale is settling in, i'm realizing, especially in light of the flash forward with Jack, that "Lost" – as the title of the show refers to more than their being on the island... they were//are all "Lost" in their lives as well.
Because of characters like Jack and Sayyid, I had never thought of it that way, because they both seem fairly "together," but seeing Jack after their return from the island, the term "Lost" has larger implications than their being on (or off) the island.
Kudos to the writers for bringing the storyline back to "civilization" half-way through the story; so many other writers would end the storyline at the same time that they get the characters off the island; this way they've made it clear that the story is about more than the characters' physical location.