Your eternal aspect is not oriented towards the past; it is always using the past as a platform for what is to come. We are always oriented towards the expansion the improvement. When you come into a new life, you close your eyes to the past, in order to open them to a new existence. The benefit of a new life is a new perspective... other than a perspective that is an accumulation of every other life as well. That would be like trying to listen to a billion channels on a radio at the same time. Our eternal being (often called a soul) manages to be all these channels at once. Which is why you can see your past lives when you withdraw your focus and re-align with your eternal consciousness like when the Buddha was meditating under the Bodhi tree.
We come into one singular life focused on this singular life.