I was traveling in a first-class bedroom on a train. I don't generally lock my door because I don't think of the train as dangerous. A white man opened the door to my room, drew back and gasped (in horror.) He had mistaken my room for his, and he obviously thought that The Creature from the Black Lagoon had come to occupy his room. I gave him one of those pursed-lip smiles, he left, and I went on with my business.

Two hours later; same man, same gasp of horror. I just gave him a look.

Two hours after that, he did it again. That Lagoon Creature must have been pretty scary. This time, I told him, "Maybe you need to keep your ticket so that you can find the right room next time. " Yes, I finally locked my door after that, more out of concern that he'd die of a heart attack outside my door than anything else.