I’m on the Pennsylvanian. As a result of being among the last one-third to board, I found myself next to a young woman who is one of those nervous, self-centered pieces of work you don’t want to find yourself next to. The train was clearly going to be full; by the time I got on, there were few empty seats left. She had all her bags piled onto the seat next to her and had settled in comfortably with earbuds in when I disturbed her peace by rudely tapping her to get her attention when she missed my initial hail.

“WHAT?” she exclaimed.

“Is anyone sitting here?” I repeated.

Instead of replying, she huffed and sighed heavily, collected her bags, and flung them disgustedly onto the upper rack across the way. Clearly, she had expected to have the only empty seat on the train to herself. Meanwhile, I smiled beatifically at the people in the line behind me, who of course were waiting for her and me to get out of their way so they could find seats, too. I had spared them from my newly discovered Center of the Universe.

I took my coat off and sat on it. Apparently, a cord must have been nearly touching her through her layered clothing, akin to the pea bothering the princess through many mattresses, because she abruptly suggested that, if I weren’t going to actually wear it, I put it overhead. “It’s . . .” within an inch of her person!

When the conductor came through to collect tickets, she seemed taken by surprise. As she rummaged frantically through her bag searching for tickets and ID, she jabbed me a dozen times or more with her flailing elbow, which, oddly, didn’t bother her given her sensitivity to touch and wasn’t supposed to bother me. Later, as she read and tossing her hair, it was all I could do not to say to her in the same nervously fussy tone she’d used on me, “Would you mind not shaking your head like that? Your dandruff and vermin are, like, you know . . .” Eventually, after I’d dozed off, she woke me up to trounce off somewhere, which gave me the opportunity to plug in my iPhone, which gave her the opportunity to harumph when she demanded her seat back. After that, I left her with her space and mine all to herself.

My Christmas wish for her: The maturity and the wisdom to understand that she is no more significant than the 7 billion other humans with whom she shares Planet Earth. And the few dozen with whom she shares an Amtrak car.

I’m not holding my breath.