Deja vu theory

I saw an unusual house out of the corner of my eye, walking with my flatmate this morning, she said something to me and it was like I flipped backwards into time, like I'd already lived this moment before. When, I wasn't sure. But there was definately an otherworldly feeling to it. So visual cue + audio clue = deja vu, (from the french "already seen.") For me thats how it usually works anyway. Two or three events will combine in my consciousness to create that feeling that something is going on. I've had a few deja vu moments lately. My theory is that it means I dreamed it before, I dreamed about seeing or hearing something and then when it happens later my subconscious remembers it. One of my friends has a different theory. She thinks that before we came to this life we saw a preview of our life here on earth, and that we remembered certain things that would happen prior to significant moments - so the deja vu triggers an awareness that something important is about to happen. Another friend said she just feels like when she gets deja vu that its a personal sign to her that her life is going in the direction that its meant to. In any case, deja vu can't be predicted. It just sort of jumps on you without any advance warning. But its usually more memorable than other random moments of my day.