Put another way, if you cannot look forward to today, you cannot look forward to tomorrow.
Put another way, the past clings, and until you can rid yourself of it, it will make you heavier and slow you down.
And if I might contradict myself (I might, in the event), if you do not know where you come from, it is impossible to know where you are beginning, when you decide where you should go.
I would actually unite these by saying that knowing who you are is really the outcome of processing the past. It allows you to begin where you are, rather than where you wish you were, or mistakenly believe you are.
All of us, I think, simultaneously overestimate and underestimate what is possible for us. Although I hate to quote him, I think Bill Gates captured this reasonably well by noting that most of us overestimate what we can do in a day, but underestimate what we can do in a year, and seriously underestimate what we can do in a lifetime, with focus, and with a plan.
But practically, for many of us, there is this whole sequence of largely unconscious emotional events which happen every morning on rising which color everything. They limit what we can see, and they do so every day of our lives, until they are dealt with. Dealing with these events is learning to begin to live consciously, and until we do that, all of us are boats on the sea without sails or rudders. I made this sound like a good thing a few days ago, and it is, but on a much higher level. In the end, none of us is really fully in control. We never know for sure what may unexpectedly burst into our lives. But this does not mean we cannot engineer and support regularities which are meaningful and healthy.