So when I watch trains, it makes me think about how much movement there is in the world. How every train has dozens of cars and every car has hundreds of parts, and all those parts and cars work day after day. And then there are all these other motions. People are born and die. Seasons change. Rivers flow to the sea. Earth circles the sun and the moon circles Earth. Everything whirring and spinning toward something. And I get to be part of it for a little while, the way I get to watch a train for a minute or two, and then it's gone.