Is Past relevant for Future?

They say, "history is the best teacher". I assume they mean teaching you to be prepared and face the future. Is past really relevant for future - then be it for an individual, a country or a civilization.
There is a lot that has happened in the past that we know today and there is a lot more that is going to happen in future that we do not know today -- so am I expected to anticipate my future based on my past. How sensible is that?
As an individual, my past was childhood and youth and my future is my adulthood and old age -- I cant take decisions or plan for my adulthood & old age based on my experiences in childhood.
As a nation India had a strange past of being economically very rich at one point of time and then eventually brought down to nothing by various invasions recorded in the history -- but does that mean, we are going to remain like that or we should plan our growth based on that? I heard a gentleman say in a TV show that India had no identity before 1947 so the history before that does not impact India's growth for future. I dont agree that India did not have an identity before 47 but I do agree that history may not necessarily drive our future.
I do not know why but there is a piece of my brain that is not supporting this fact of past being relevant for future but my heart says, it does. Had Prithvi Raj Chauhan learnt from even one of his 16 past incidents, he would have never lost to Mohammad Ghori. Had India evaluated their security based on the past, 26/11 could have been dealt better.
But then I have big question. What is the need to be prepared for future? My past is my memory. Present -- I donot even get to realize when it became my past. Let my future remain a mystery to me. I dont want to get prepared. Coming to world was a surprise to me and many others. My end shall repeat the gesture. I will not let my past decide my future.
I am waiting with my arms open for it to come to me and hug me with its mystery and unknown. No turning back from here on.