Of course, [[LOST SPOILERS FOR THOSE PLANNING TO WATCH THE DVDs]]:
even the creators of Lost failed to realize that, when we were treated to multiple seasons of time travel, ridiculous plot twists that were not character based and were never followed up on, one of the main characters being a zombie, and a second-to-last episode that had exactly one scene with those iconic characters (and that was a scene we had already seen).
It's no coincidence that almost every "flash-sideways" the characters had in the last episode involved events in Season 1 and 2 - or back when the show was truly spectacular, or that the much-ballyhooed finale ended with call backs to the (brilliant) pilot.