nut graf:

Years ago, I was habitually late. “I can’t help it!” I declared to an expert in time management (I’d turned my effort to reform into a magazine article, as writers do, which gave me the excuse to seek professional help).

“Have you ever missed a plane?” she asked. I had not. “Then you can help it. You just care more about yourself than about the needs of others.”

I may be naturally reserved, and more comfortable alone than I will ever be in a crowd, but I am not at the mercy of my nature. There are many excuses for failing to conduct ourselves with courtesy, for avoiding gatherings and conversations we don’t think we will enjoy, or for just putting on our pajamas and staying home. Too many of them boil down to just that one thing: We care more about ourselves than about the needs of others.

That’s not about introversion. It’s just an ordinary version of selfishness.