Scientifically, time is an oddity. Relativity theory treats it as one dimension of reality. Time is tantamount to the movement of mass in spacetime. So, time reversal, or retrocausality, has been proposed as a way to interpret antimatter—a positron being an electron that's traveling backwards in time. Also, at a theoretical level, the equations that govern electromagnetic radiation don't distinguish between time going forwards or backwards. And yet, in the macro-world of the everyday, we clearly can't move temporally backwards, but only forwards. So how can this existential difference be reconciled?