The more interesting question is why do we have deja vu? Is it a reworking of a Divine plan that tells us we are on track? Is it a trick of the brain? What's funny is that the deja vu is always immediate. We know it when we are in it. Perhaps we are dizzy and our brains are trying to catch up. The instances that I've always had involve people saying the things I've heard before. Either that's deja vu or we hang around extremely predictable people.