I read one explanation of deja vu long time ago. The brain is divided in two halves. It's just that one half of the brain already experienced the reality whereas the other hard is a bit "slow". So when the slower half catches up, it seems like you experience something that has happened before.

Hope I'm making sense.

No, this theory has nothing to do with future/past/present.

A external event happens, black cat walks past door (in first Matrix film). The right brain receives the input and registers it. Left brain receives input split second slower. Anyway both sides are connected, and as a result you get the feeling you saw that cat walk past before. Clearer?