Quote Originally Posted by Magus of Zeal View Post
I think you are wrong that he can time travel.

I think he has already lived EVERYTHING on the island from the moment the failsafe key was turned.

Think about it this way.

Des turned the key. His "life" flashes before his eyes right? Well also what flashes was an alternate reality where he didn't turn the key. So when he goes about on his days he see's differences in this alternate reality and present reality (ie Desmond saw that in the alternate reality lightning struck Claires tent killing Charlie so he changed it.) That is how he can "future see" and that is why the "flashes never stop."

Tell me what you think.
Well, that's exactly what I thought too at first (I kept trying to convince my sister of this until the end of the episode) but I think now that the whole vision was just the Island telling him that things couldn't have turned out well no matter what he would have done to keep his relationship with Penny.

The flashes are merely coming every once and a while as a symptom of him using the failsafe key, but he hasn't lived through all that.