But we were holed up in a classroom with Professor Smith (his real name; you know I wouldn't make up a name like that). He was trying to teach us the elements of trigonometry.

We had almost mastered sine, cosine and tangent, when Smith embarked on interpolation, the technique of finding a function's value that hid between two values in our trig tables.

After exposing the mysteries of interpolation and citing a few examples, Smith became aware that most of the minds in the class had wandered.

A long-time teacher, Smith knew the right thing to do. He offered analogies, some of them rather strange. But that only plunged the class further into darkness. Frustrated, he spoke more slowly, more emphatically, then more loudly. This woke some of us.

Caught up in his own near-hysteria, Smith lost control and our attention again-which triggered almost panic in our mentor. In retrospect, I think the right thing would have been for Smith to dismiss the class with instructions to go outside and smell the air.

He finally seized the class's attention firmly, largely because he had a reputation for being tough. But then he began to boil and the class began to freeze in terror. He had control of the class, but he had lost his grip on the subject.

He vaguely realized what was happening and wanted desperately to do the right thing. Recognizing that he had lost the message, he became more frantic, shouted louder and, marching through the aisles between our seats, began to pound his right fist into his left palm.

He must have known that was not the right thing to do, yet he started screaming. "This is important. You must learn this! You must understand this! Does everybody get it?" And in a final crescendo, he thundered, "DOES EVERYBODY GET THE POINT?!"

Nobody breathed. Then, for some reason I cannot fathom to this day, I burst out laughing. The class was thunderstruck. All eyes were glued on me as my classmates knew I had gone mad.

In a last gasp, Smith screamed. "YOU! What are you laughing at?"

Still laughing, I replied, "I got it."

The tension snapped. Smith

sat down and collected himself for half a minute. "Look," he said quietly, "here's how it works." In simple terms, without abstruse analogies, he explained interpolation so that everybody understood it immediately as a simple tool.

But what I had done wasn't the right thing. Or was it?