I might be forgetting something, but I was confused as to how/when Jack and Julia were parents to David. That really surprised me. Can anyone help explain that?
David did not exist. He only existed in Jack's flash sideways I think to represent him getting over his daddy issues. Jack was able to be the dad to his "son" that christian could never be to him.
as far as juliet is concerned I think it was just the writers way of getting her back in the mix so she could hook up with sawyer again in the afterlife.
this article helps to sum things up as best as possible.
http://www.tvsquad.com/2010/05/24/lost-finale-theories-explanations/?ncid=webmaildl2
I think one of the best things about being a fan of lost was that the viewers theories always seem to be better and more original than anything the writers could write up. It was more fun trying to figure out what was going on than actually being told by the writers what everything meant.

) that is really confusing me.... I get that the sideways were their purgatory. If you go with the theory that the 815 crashed and what happened on the island was real and all the flash forwards were real, then HOW is Clarie in the church at the end with Aaron as a newborn? He supposedly got off the island with Kate and was 3 when she left him. Even if he died as a child he wouldn't be a baby. So, does that mean the flashforwards weren't real b/c he died soon after they got to the island? I know Christian said, you all created this to reconnect, but he was already connected to the plane and the island etc.. 
