It was late afternoon in late January. I was sitting on my own in a compartment of a Berlin–Warsaw train. There was only two or three minutes until its departure, and I assumed that I would have the compartment to myself when this guy came in. He didn’t say hello or ask if the remaining seats were free, as it was customary on the Polish trains, just took his seat near the door and put his small rucksack and two shopping bags on a shelf above him. Although his behaviour was verging on being rude, I felt instant sympathy for him, in part because behind his actions I sensed a desire to be invisible rather than rudeness and in part on the account of his similarity to my old friend from university, with whom the…