At the lesson of social problems, the professor raised a black book and said: “This book is red.”
At which all the students started by saying: “No!”
He repeted: “Yes, red.”
And the students again: “It’s not like that.”
The profesor turned the book, and the back cover was red.
Then he said: “Do not tell someone that he is wrong, until you look at the situation from his point of view.”