From Paulo Coelho's blog:
A Samurai who was known for his nobility and honesty, went to visit a Zen monk to ask him for his advice. When the monk had finished his prayers, the Samurai asked,
"Why do I feel so inferior? I have faced death many times, have defended those who are weak. Nevertheless, upon seeing you meditating, I felt that my life had absolutely no importance whatsoever."
"Wait. Once I have attended to all those who come to see me today, I shall answer you."
The samurai spent the whole day sitting in the temple gardens, watching the people go in and out in search of advice. He saw how the monk received them all with the same patience and the same illuminated smile on his face.
At nightfall, when everyone had gone, he demanded, "Now can you teach me?"
The master invited him in and lead him to his room. The full moon shone in the sky, and the atmosphere was one of profound tranquility.
"Do you see the moon, how beautiful it is? It will cross the entire firmament, and tomorrow the sun will shine once again. But sunlight is much brighter, and can show the details of the landscape around us: trees, mountains, clouds. I have contemplated the two for years, and have never heard the moon say: why do I not shine like the sun? Is it because I am inferior?"
"Of course not", answered the samurai, "the moon and the sun are different things, each has its own beauty. You cannot compare the two."