One, None and a Hundred Thousand by  Luigi Pirandello 

“What are you doing?” my wife asked me, as she saw me lingering, contrary to my wont, in front of the mirror.
“Nothing,” I told her. “I am just having a look here, in my nose, in this nostril. It hurts me a little, when I take hold of it.”
My wife smiled.
“I thought,” she said, “that you were looking to see which side it is hangs down the lower.”
I whirled like a dog whose tail has been stepped on:
“Which side hangs down the lower? My nose? Mine?”