It was only the third day of the school year, and Stephen came in late to math, the last class of the day. He was huffing and puffing as he lugged in a cello in a case that was heavier than the cello itself.

“Do you play the cello?” Mr. Davidson, the teacher, asked.

“Yes,” Stephen replied. “I’m sorry I’m late. I hope you won’t mark me tardy. It’s a long way from the orchestra room, and it’s impossible to hurry with something this big.”

“Couldn’t you just leave it in the orchestra room and get it after school?” a girl asked.

Stephen shook his head. “I normally would, but I have a cello lesson right after school, and I don’t have time to get back to the orchestra room and make it to the lesson on time. So I had to run get it and bring it here so I can leave immediately after class is over.”

“Why did you choose to play the cello?” a boy asked

“I love the sound of the cello the most of all instruments,” Stephen replied.

“It would have been easier to choose something like a flute,” the boy said. “You could haul a flute around with no trouble.”

The students started teasing Stephen about his choice in instruments and how big it was. Stephen just smiled and took the good-natured ribbing. But it seemed to annoy Mr. Davidson.

“All right, everyone,” Mr. Davidson said. “I, too, think that the cello is one of the best sounding instruments. In fact, I like it enough that I am not only going to forgo Stephen’s tardy, but I am going to give him five extra bonus points for the day for his good taste and for his diligence in practicing and taking lessons.”

A girl pulled a clarinet from her backpack. “How about bonus points for a clarinet? I practice diligently and take lessons, too.”

“I might consider a few points, but hauling around a clarinet does not compare in dedication to a cello,” Mr. Davidson said.

“I used to play the cello,” Sally said. “Can I get an extra five points, too?”

“You used to play it?” Mr. Davidson said. “Why did you stop?”

“I quit,” Sally replied. “It was too hard to haul around and practice.”

“Quitting just because it was hard should be a negative five points, not a bonus,” Mr. Davidson said.

“Did you ever play an instrument, Mr. Davidson?” one of the students asked.

Mr. Davidson nodded. “It just so happens that I love the cello, as well. When I was your age, I practiced it for an hour every night.”

“Do you still play?” Stephen asked excitedly.

“No,” Mr. Davidson replied. “I must admit that I wasn’t the most talented musician, and my family begged me to stop practicing.”

“So you quit, too?” Sally asked with a snicker.

Mr. Davidson turned to her. “I didn’t quit. It is true, like I said, that my family begged me to stop, but I didn’t quit.”

“So what happened that you don’t play anymore?” Sally asked.

“When I continued to practice, despite my family’s pleas, my cello disappeared, and I never saw it again.”

And then Mr. Davidson said in final, “That’s why, lucky for you, I teach math and not music.”