I'm standing on the subway platform at my stop.
When I look across the center track, I see the platform opposite, where a train going "the other way" is just pulling in. The people that get out seem foreign and distant to me, and in fact I think of their side as a different stop entirely, despite the realization that in a few hours I will also arrive like them, going "the other way" but thinking of it as perfectly natural then: a return. It's unimaginable to me now.
There is a strong directional bias at the stop you call "your" stop, even if only one platform serves both directions. One side is for waiting, peering down the tunnel, pacing around. The other is for disembarking and scrambling up the steps. But it goes beyond this, and it goes beyond the mental vectors of expectation.
Why is it so hard to regard these people arriving as part of the same continuum--to see yourself in their midst?