I ignore the prediction aspect of deja vu. It never happened to me. If it did, I would have dismissed it as coincidence.

I believe that some people seem able to make good predictions based on some type of subconscious processing of data. In most cases, these people have a lot of experience relating to what they are predicting. The best example I know of has to do with playing poker with experts (I am not one). For these people, Poker is not a card game, it is a people reading game. When deciding to bet, raise, or fold they do a good job of predicting how good the mark's hand is. I am not talking about obvious "Tells." I am referring to some type of subliminal clues.

Aside from the above, I attribute anecdotes about successful predictions to be due to coincidence, faulty memory, hallucination, after-the-fact fitting of the prediction to the events (Nostradamus, for example), deliberate exaggeration (Id est: lying), non-deliberate exaggeration.