What is TODAY ?

A very small and simple question, the answer isn't small or simple. Someone once said ,"Today is yesterday's tomorrow." Someone else said,"What we are today is the sum total of our yesterday's." The mistakes we make are learning experiences that aid in making us who we are today. Almost everyone has said, " If I could only go back and change something." If we did go back , it would change everything from that point on, even us , to the extent that we would not be the same either. Sometimes I'm not content with myself but I know me. If my life had been different, maybe I wouldn't be any better off. I'd just be different.