I often wonder if the writers have the whole plot written down from beginning to end or if they're making it up as they go. But then it's way too complicated and interwoven to do that... they'd be LOST also! I love the way little details from seasons ago, come back and tie in to the present shows... and then raise MORE questions.
The thing about it that keeps me coming back is that there WILL be a conclusion and all will be revealed, unlike Twin Peaks which just stopped. Miss an episode and you won't understand something later. Sometimes I think about just recording a whole season instead of watching weekly, then watching the whole season at once. But, no, I need my weekly 'fix'.
This truly is "Must See TV".