"We're sure in the weeks to come, there will be lots of discussion about the distinctions between 'purgatory' and 'heaven,' and 'the afterlife' and 'being dead,' and 'misleading information' and 'flash sideways is not the island,' and 'when did the Lost creators actually know how the show was going to end' and 'why didn't Darlton care at all about the show's mythology?!' — but in the instant aftermath of the finale, it seems that something sort of like purgatory, insofar as purgatory is a place full of dead people, did in fact have something to do with this here series called Lost."
Hey, you know what would really be funny? After we really die, if we find ourselves somewhere and we're talking about the distinctions between "purgatory" and "heaven," and "the afterlife" and "being dead," and somebody says "Deja vu! This is like exactly the same conversation I had after the last episode of Lost."