Power of now

We spend most of our time in repenting what we did in the past . We also spend considerable amount of time in thinking about the future. Thinking of past and future are a waste of time and energy . They have either gone or yet to come. The time that has passed by cannot be altered by you going into the past. Similarly you cannot go into the future as it is still unknown. The only greatest power that one has is that of NOW . You can take your learning from the past , work in NOW to create a good future. So my experience says that it is good to always believe in the power of NOW to harness the greatest power . I have seen all through my surrounding that most successful people act on what is there in hand rather than spending time thinking about the unknown