A professor went to live in a primitive African tribe as a part of his expedition. He spent years there, teaching them to read, write, mathematics and science.
One day the wife of the tribal leader gave birth to a white baby. The tribe was shocked. Then the leader pulled the professor aside and said: “Look at this! You are the only white man we have ever seen, and this woman’s giving birth to a white baby. No need to be genius to understand what has happened!”
The professor answered: “No, leader, you are mistaken. What happened to you, is a natural phenomenon called albino. Here, look at this field! All sheep are white, except the one black. Sometimes, such things just happen.”
For a moment, the leader was silent, then he said: “Look, you say nothing more about this sheep, and I say nothing more about this white child…”