Time Symmetry: Why Does Time Seem to Move Forward? (String Theory)

The space dimensions are interchangeable, but time is distinct because it seems to move in only one direction. This doesn’t have to be the case. In fact, the mathematical laws of physics work either way, even in a universe where time could run backwards.
But time doesn’t run backwards at all, and a theory of everything would need to explain this discrepancy between the mathematical symmetry of time and the physical asymmetry of time that you observe every time you’re running late for a meeting.