When you raise a dog, a lot of people like to train them, so that they can be well behaved and impress your friends. My dog, Zeus, is a well behaved German Shepherd, who is one of most timid dogs I've ever seen.
Zeus is frightened very easily, and can't stop checking around himself constantly. He does this so much, that he'll bump into posts or slip over, all because he can't stop looking behind him.
The amount that I've had to tell Zeus to calm down and pay attention has therefore got stuck in my mind, as I could relate it to the way I, and many others around me, can be.
People often get so fixated on their past, endlessly worring about their experiences and struggling to move on, that they can miss everything that's happening to them at that moment, which nine times out of ten will be more interesting, and maybe the solution to your problems.
Therefore, like I would say to Zeus, if you want to avoid differnet bumps and dips as you go on, you have to stop looking back.