We have to look ahead on the road of life, while ´driving´ through our life.
It is like driving a car. If we fix our attention ahead on the road, we can proceed, drive, and arrive at our destination.
But if we look too much at the mirrors of our car, all we can see, will be what is behind us.
By looking too much behind us, we can not continue ahead, and we can not arrive at any destination. We will not be able to progress and grow spiritually.
Also, if we look too much into the mirrors of our car, we risk of having an accident.
So with our life, like Apostle Paul said, that we should forget what is behind, the past, and look forward of what is ahead of us.
Our past is a history, and what is left is the present and the future.