Recede behind my train and
converge into one.
How banal. But I love watching out the front or back of the train, being mesmerized as the tracks go by. It's rare these days to get to watch out the front; they've got the engineer boxed into his* private compartment and unless he's breaking the rules by leaving the door open, we can't look out. So the end car, the erstwhile caboose, offers a more consistent view, and a more wistful one: where we've been, not where we're going. It also offers, on straight track, a perfect illustration of the powers of perspective. The parallel tracks appear closer and closer together, until they might as well be one.
*Always male - I think I've never seen a female engineer on one of my commuter trains. Conductors, yes - but not the engineers.