A man is driving down the road and breaks down near a 
Buddhist monastery. He goes to the monastery, knocks on 
the door, and says, "My car broke down.  Do you think I 
could stay the night?"

 The monks graciously accept him, feed him dinner, even 
fix his car. As the man tries to fall asleep, he hears a 
strange sound.  The next morning, he asks the monks what 
the sound was, but they say, "We can't tell you. You're not
 a monk."

 The man is disappointed but thanks them anyway and goes 
home.               

 Some years later, the same man breaks down in front of the 
same monastery.  The monks again accept him, feed him, even 
fix his car. That night, he hears the same strange noise 
that he had heard years earlier.

 The next morning, he asks what it is, but the monks 
reply, "We can't tell you. 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, 
grasshopper, you will become a true 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 traveled the earth and have found what you 
have asked for.  There are 145,236,284,232 blades of grass 
and 231,281,219,999,129,382 sand pebbles on the earth."

 The monks reply, "Welcome. You are now 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 right behind that door."

 The man reaches for the knob, but the door is locked.
 He says, "Master, give me 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
 demands 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.  So it went until the man had gone through 
doors of emerald, silver, topaz, amethyst, and 
gold.

 Finally, the monks say, "This is the last key to the last 
door." The man is ready.  He unlocks the jade door, turns 
the knob, and behind that door he is amazed to find the 
source of that strange sound.

 But I can't tell you what it is, because you're not a 
monk.