The monks graciously accept him, feed him dinner, and even fix his car. As the man tries to fall asleep, he hears a strange sound; a sound like no other that he has ever heard. The next morning, he asks the monks what the sound was, but they say, "We can't tell you because you're not a monk."
The man is disappointed but thanks them anyway and goes about his merry way. Some years later, the same man breaks down in front of the same monastery.
The monks again accept him, feed him, and even fix his car..
That night, he hears the same strange mesmerizing sound that he had heard years earlier.
The next morning, he asks what the sound was, but the monks reply,
"We can't tell you because you're not a monk."
The man says, "All right, all right. I'm dying to know.
If the only way I can find out what that sound was is to become a monk, how do I become a monk?"
The monks reply, "You must travel the Earth and tell us how many blades of grass there are and the exact number of sand pebbles. When you find these numbers, you will become a monk."
The man sets about his task. Some forty-five years later, he returns and knocks on the door of the monastery. He says, "I have travelled the Earth and devoted my life to the task demanded and have found what you had asked for. There are 371,145,236,284,232 blades of grass and 231,281,219,999,129,382 sand pebbles on the earth.
The monks reply, "Congratulations, you are correct, and you are now considered a monk.
We shall now show you the way to the sound."
The monks lead the man to a wooden door, where the head monk says, the sound is behind that door.
The man reaches for the knob, but the door is locked. He asks, "May I have the key?"
The monks give him the key, and he opens the door.
Behind the wooden door is another door made of stone... The man requests the key to the stone door.
The monks give him the key, and he opens it, only to find a door made of ruby.. He demands another key from the monks, who provide it. Behind that door is another door, this one made of sapphire. And so it went on until the man had gone through doors of emerald,....
....silver, topaz, and amethyst.
Finally, the monks say, "This is the key to the last door."
The man is relieved to be at the end. He unlocks the door, turns the knob, and behind that door he is astonished to find the source of that strange sound. It is truly an amazing and unbelievable sight ....
.... But I can't tell you what it is because you're not a monk.
Graham
Right there toward the end I had a feeling I was about to be had. 
...in the meantime I'm off out on the lawn with a pencil and pad 
