It is so very important that we all try very hard not to dwell in the past. It gets us absolutely nowhere. It is a different story, of course, if we learn from past experience and rationalize it to better our lives in the future.
Ever notice that young children often experiment with walking backwards? They like to see how far they can get and how fast they can go while their eyes are fixed on where they have just been, rather than where they are going next.
Why do we adults rarely do this? Because we have all learned at an early age that it is a bad idea. The same thing, then, should apply to "backward" thinking or reflecting.
Every so often I find that it is in my best interest to consider the amount of attention that I am giving in my life to an issue that really relates to the past and is now totally out of my control. Invariably this little exercise in self-shaking results in an abrupt turnaround for me.
It feels much better when I can see where I am going. Kind of helps me get there.