The Professor and the Farmer

As the story goes, a professor and a farmer were traveling together by train. After several days, they tired of talking and reading, so the professor suggested they play a game of riddles.

“Every time you miss a riddle, you give me a dollar, and every time I miss a riddle, I’ll give you a dollar,” said the professor.

“You’re better educated than I am,” the farmer pointed out. “I’ll give you 50 cents.”

The professor agreed, and the farmer made up the first riddle. “What has three legs walking and two legs flying?” he asked. The professor didn’t know, so he gave the farmer a dollar. The farmer didn’t know either, so he gave the professor 50 cents.

What’s the moral of the story?