A philosopher made an appointment with Nasrudin, to have a scholarly discussion. When the day came, the philosopher dropped by Nasrudin’s house as planned. However, Nasrudin wasn’t home. The philosopher angrily took his pencil out of his pocket, wrote “Asshole” on Nasrudin’s door, and then left.
When Nasrudin finally came home he saw this, and realized that he had missed his appointment. He dashed off to the philosopher’s house.
“Forgive my error,” Nasrudin told the philosopher when he got there. “I totally forgot about our appointment today. But when I got home and saw that you had written your name on my door, I immediately remembered, and came here as fast as I could.”