One day, a professor entered his classroom and asked his students to prepare for a surprise test. They all waited anxiously at their desks for the exam to begin. The professor handed out the exams with the text facing down, as usual. Once he handed them all out, he asked the students to turn over the papers.
There were no questions—just a black dot in the center of the paper. The professor told them, “I want you to write about what you see there.”
At the end of the class, the professor took all the exams, and started reading each one of them out loud in front of all the students.
All of them, with no exception, defined the black dot, trying to explain its position in the center of the sheet. After all had been read, the classroom silent, the professor explained:
“No one wrote about the white part of the paper. Everyone focused on the black dot—and the same thing happens in our lives. The dark spots are very small when compared to everything we have in our lives, but they are the ones that pollute our minds. Take your the eyes away from the black dots in your lives. “