You never watched Lost, did you?
(Good for you.)
The entire series was a prequel to itself.
Seriously: as soon as you get used to the fact that every episode is mostly flashback about how the characters got to where they are, they go back in time. Then they start having falshbacks in the past. Then those flashbacks have flashbacks.
Nope...but now you have me curious.
;D
[it sounds like Once Upon A Time on steroids]