a tunnel vision

Once upon a time, I sat on a moving subway train. Another train ran on an adjacent track, mere feet away from my train, going in the same direction, and at the same speed. The two parallel trains creates a strange sensation, and you start to feel like you may not be moving at all, if it weren't for the periodic beams that flash by every half second. I saw an older gentleman in the other train's car across the tracks. We faced each other, sitting, and probably both enjoying our weird race. In a small way, I relish when this happens. Finally, after a minute or so, the two trains veered and the distance between us grew more and more until we were seconds away from the other train disappearing into some other tunnel. I contentedly watched, and as the trains moved further and further apart, I mouthed, "goodbye" which the man saw. He smiled, I smiled, and in a flash, he was gone.