One day, a monk decided to meditate alone, away from his monastery. He took his boat out to the middle of the lake, moored it there, closed his eyes and began to meditate in the middle of the crystal clear waters.
After a few hours of undisturbed silence, a boat collided with the monk’s. Eyes still closed, he felt his anger rise, and when he opened them, he was already ready to yell and yell at the boatman who had so carelessly disturbed his meditation on him. But when he opened his eyes, he was surprised to find that it was an empty boat that had hit his.
It had probably broken free and was floating in the middle of the lake. At that moment, the monk had a great realization. He understood that the anger was inside him; he simply needed the blow of an external object to cause it. From then on, whenever he encountered someone who irritated or angered him, he reminded himself that the other person was just an empty boat, the anger was inside him.