"What do you think they [Deja vu] are? Simply the proof that life is boring, that it never really changes and that we are bound to go through similar situations over and over again? In other words, a glitch in the brain that causes it to mistake the present for the past. "
I don't really think it's either of those. I think we won't really know what Deja vu is really. Maybe we'll never know. I think that, like a lot of tangible/probable things, Deja vu is simply ourselves trying to tell ourselves things about things that aren't ourselves (although sometimes the things are about ourself). does that make any sense to you? it almost doesn't make sense to myself.
picture that our brain is a radio, and all we can hear is all that we can understand and comprehend. We can understand things that we didn't understand in the past, just as we can hear things we've never heard before. Also, we can understand songs better in the future, even if we understand them already. Also, there are things we'll never understand, and never hear. So I think that all the things we don't understand are like different radio stations we just can't tune into. So also, MY POINT FINALLY (yay!) is that I think Deja vu is just little samples of songs we haven't heard yet, and we wont understand the samples until we hear the whole song.