The past and future are inaccessible and should not be counted as real. They only exist when we imagine them.
We only have agency in the present. The past exists only in memory, from the perspective of the temporally present creature.
As a result, the linear is something that only exists as an abstract - used to explain the gap between memory and the present state or the future state to come. The past is not the present is not the future. The connection between them is something we imagine in order to understand the existence of memory. That doesn't mean the linear doesn't exist - only that our understanding of it is artificial.
Curiously, our minds do not seem to work linearly. Linear thinking seems to be a way to explain our thoughts, but our brains do not follow its logic. Or thoughts jump around and we experience the sender of several ideas at once rather than a smooth passage between them.
In the same way that Writing puts our thoughts in order, or comprehension of time puts order to our memory and the universe.
In this way, the invention of literature and the telling of story probably influenced our inclination to attempt to think linearly. As #Marshall McLuchan says, the medium is the message. So, as we developed story, that story developed the way that we think about the world. story shapes the way we think about the world