Storie.

Two firemen go into a forest to put out a small fire. Afterward, when they emerge and go over to a stream, the face of one is all smeared with black, while the other man’s face is completely clean.

Which of the two will wash his face first?

The one with the clean face. Because, the one with the dirty face will look at the other man and assume that he looks like him. And, vice versa, the man with the clean face will see his colleague covered with grime and say to himself: I must be dirty too. I’d better have a wash.