The answer is, there is no such thing as time as we know it. Time is not a linear element as Isac Newton said, some scientists in the 70's where agreed about it. It could be that some of the dèja vu's already happened somewhere, sometime. The fact is that cause time is not linear, events don't happen in a linear order. The only thing you should do is tuning yourself to the real time. So you can even predict the future because it has already happened somewhere in time.
Greetz,
Jonathan
Greetz,
Jonathan