A man's car broke down as he was driving past a beautiful old monastery.  He walked up the drive and knocked on the front door of the monastery.  A monk answered, listened to the man's story, and graciously invited him to spend the night.

The monks fed the man and led him to a tiny chamber in which to sleep.  The man thanked the monks and slept serenely until he was awakened by a strange sound. The next morning, as the monks repaired his car, he  asked about the sound that woke him.  The monks said, "We're sorry.  We can't tell you about the sound.  You're not a monk."

The man was disappointed, but eager to be gone, so he thanked the monks for their kindness and went on his way.  During quiet moments afterward, the man pondered the source of the alluring sound.

Several years later, the man was driving in the same area.  He stopped at the monastery on a whim and asked admittance.  He explained to the monks that he had so enjoyed his previous stay, he wondered if he might be permitted to spend another night under their peaceful roof.  The monks agreed and the man stayed.  Late that night, he heard the sound.  The next morning, he begged the monks to explain the sound.  The monks said, "We're sorry.  We can't tell you about the sound.  You're not a monk."

By now, the man's curiosity had turned to obsession.  He decided to give up everything and become a monk, if that was the only way to learn about the sound.  He informed the monks of his decision and began the long and arduous task of becoming a monk.

Seventeen years later, the man was finally established as a true member of the order.  When the celebration ended, he humbly went to the leader of the order and asked to be told the source of the sound.

Silently, the old monk led the new monk to a huge wooden door.  He opened the door with a golden key.  That door swung open to reveal a second door of silver, then a third of gold, and so on until they had passed through twelve doors, each more magnificent than the last.

The new monk's face was awash with tears of joy as he finally beheld the wondrous source of the mysterious sound he had heard so many years before.

But, we can't tell you what it was.  You're not a monk