Imagine a baseball thrown thru the air. A high speed camera takes pictures of it showing very great detail -- names, laces, etc. Someone shows you a picture -- can you tell what direction it is travelling? or even if it is moving? NO. You would have to know where it was thrown FROM to know what direction it is going. In times of high change, it's good to know a little bit about the PAST to understand the present freeze frame of the NOW and project to some degree of accuracy where we are GOING (The Future).