One thing really puzzled me on my flight back home last week. On every passenger aircraft, they have the same plaque above the sink: “As a courtesy to the next passenger, may we suggest that you use your paper towel to wipe the sink.”

You may, but I won’t. I don’t get it. I mean, a sink is expected to be wet. That’s its essential function. I have never known of anyone being offended by the sight of a damp sink. So what does the ubiquitous sign represent? Someone high-up in the air industry who has a peculiar phobia of sharing a sink? I really have no idea.