The passenger was excited by the fact that his seat mate had his right arm in a sling, and the following dialogue occurred:
“You broke your arm, didn’t you?”
“Well, yes, I did.”
“Had an accident, I suppose?”
“Not exactly. I did it in trying to pat myself on the back.”
“My land! On the back! Now, whatever did you want to pat yourself on the back for?”
“Just for minding my own business.”