I think it is just something that proves my theory that time is not constant. I think it skips around, causing things to happen twice or for us to know what will happen in the next minutes or so. I have had Deja` Vu four hundred and thirty-two times this year alone. I think it happens to me quite often. I usually can know about whole conversations or scenes ahead of time. Sometimes I change it around if I don't like the outcome. I think Deja` Vu is a way of getting us to think deeper about time. I feel neutral about it, but I do find it interesting a times. Other times, I get distracted and it is quite annoying.
Anyway, that's just my thoughts. Don't listen to me. XD