I end up at McDonald’s usually because it’s nicely lit and makes for a convenient place to get picked up by my Uber or Lyft, especially when I’m in an unfamiliar neighborhood. My order is always simple: regular coffee, fries, or a Hi-C. Today, there were only two of us in the dining area: me and a tall African-American man dressed to perfection. Half the restaurant was closed off for construction, so we were confined to a tight, awkward space. I was negotiating my cane, two boxes filled with shopping items, and my order, making every movement a struggle. Since we kept passing each other repeatedly in this cramped area—and because I couldn’t help but stare at his flawless brown snakeskin shoes and impeccably coordinated corduroy and layered coat—I felt compelled...