My car not only has a rear view mirror, but it also has mirrors on either side. All three of these mirrors are designed to help me see what I have just passed or what is coming up behind me. I find it helpful to use these mirrors as I drive.
However, if all you do when you drive is look behind you, sooner or later you are going to have a wreck. Most of our attention needs to be spent looking forward, out the front windshield.
So it is with life. We need to spend the necessary time to reflect on the past, so that we can learn from our mistakes. After all, those who do not learn the lessons from the past are doomed to repeat them. Our main focus should be on the future - our hopes, our dreams, our aspirations and what it is going to take to see them through.