deja vu...nah not the matrix one

Have you sometimes felt at a particular moment in your day2day life that you have been through all of this?, well i beleive this happens to all of us and the reason, i beleive is that we all think in circles, its just like sometimes a tune or a music that you have heard sometime back (and although you have not been thinking of it in any way) suddenly plays in your head and you are humming it or singing it and it keeps on playing non-stop in your head, now this is what i'm talking about, i beleive that this was a core point in one of revolution of your thought flow
and with another thought process you are just passing by this point and its just interfacing! i know this thought is so hi-fi and i got no theory to support it but give a thought maybe a tune is playing in your head right now in this very moment!