I've only had a few deja vu experiences that I can remember. What I remember more though are times when I've had the opposite feeling of a deja vu. For example, I can be driving down the street on a very familiar route and I turn onto another street (still familiar) and suddenly everything looks very unfamiliar and I don't recognize where I am. This feeling lasts for less than a minute then suddenly I know where I am again. It's a very odd sensation.