de ja vu?

I read a book that had an explanation, it said that before we are born we are shown in some way a flash of our life, like a movie sort of and when we get that feeling we are actually remembering something we saw, and when this happen is supposed to prove we are where we are supposed to be...heavy hey...then then is the story that when we die we are again shown a flash thus what is said our life flashes before us....