The purpose of human existence seems to be to bring order to everything in this universe. Putting physics and math behind everything, defining everything, determining how things start and how they end.
It’s in our very nature to see past, present, and future as one timeline.
But the past isn’t a timeline that exists today . . . nor do our predictions of the future exist on that same timeline.
It’s in the manner we think (always wanting to bring order to a disordered universe), that forces us to perceive things in terms of inputs and outputs, origins and endings.
We exist now, not in the past, not in the future, but now—the present. That’s the only timeline we really need to care about and understand.