Hind site is 20/20, I hear this frequently.  Isn't it amazing that we live in the past and chase the future?  Why can't we live for the moment.  I don't know if there is anyone else out there who is constantly reminded of past mistakes.  We can only see our past and never our future, but yet we chase what we cannot see and live in the world, most of us, regret.  What if we took the time to live for the moment, to make the best out of "today" instead of the most of tomorrow?  No one, that I know of, is promised a "tomorrow."  We are never guaranteed another breath or to see another sunrise or sunset.  We are just promised the "now!" 

How many times have you said "if only I could go back and change what I've done"; or, "tomorrow I will do better?"  What if we say today will be good, I can't change yesterday and I don't know about tomorrow.  What change would we make in the "moment?"

Yes, our past makes us who we are today and we cannot change it but we can be forced to be better individuals.