Deja Vu is explained in the wikipedia as follows:
The experience of déjà vu is usually accompanied by a compelling sense of familiarity, and also a sense of “eerieness,” “strangeness,” or “weirdness.” The “previous” experience is most frequently attributed to a dream, although in some cases there is a firm sense that the experience “genuinely happened” in the past.
“déjà vu.” Wikipedia. Wikipedia, 2005. Answers.com 22 Oct. 2006.
http://www.answers.com/topic/d-j-vu
I’ve developed many theories of Deja Vu over the past years.
One such theory (affirmed in the wikipedia entry) is that when we dream, we sometimes see things that are likely to happen in our future. When the dreampt event then occurs we are reminded of that dreamscape.
Another theory (this one is not in the wikipedia entry) is that some spiritual guide gives us this feeling to show that the current path we’re on is the correct one. Do you remember the scene in “The Exorsism of Emily Rose” where the female lawyer finds the locket on the ground? Deja Vu would be a much more subtle form of that.
I can’t remember why I started typing this, but I’d be interested in hearing about your experiences or thoughts on this strange feeling.