You’re at a train station. You notice trains that pass by and stop, and others that pass by and continue moving. The few that make a stop stay from duration of moments to lifetimes. Each train leads to a different destination. Some trains take round trips and ultimately end back where they started, others actually reach a final destination. If you catch the right train you will never have to unboard; however, if you should be unfortunate enough to take the wrong train, you will be dropped off in the middle of the railroad and forced to take the painful walk back to the station. When you get back to the station and see the same train do you board it? But the question is, why is it back? Is it just another round trip? Perhaps. Or perhaps it came back for you to make up for its initial mistake.
(Wrote this a while back, probably around a year or two ago but never posted it. Not sure why.)