This is my favorite joke to tell. A man's car breaks down outside of a monastery.

So a man is driving home from a buisness trip. He has a pretty low paying job, so obviously he doesn't have the best of cars.

After a few hours of driving, he drives past a monastery. That kind with all the monks.

And holy tits, his car breaks down right in front of the monastery.

Being a man of God, he obviously figures, "I bet the monks will let me stay with them while my car is repaired." So he goes to the front gate and knocks on the door. A man in robes answers.
He tells the monk his predicament and the monk, being a monk, lets him stay the night, and even helps with repair costs for his car.

While the business man is sleeping that night, he hears this strange noise.
It just perplexes him, and for the life of him, he can't figure out what it is. He decides when he wakes up in the morning, he'll ask the monks about it.

When he wakes up, he finds the monk who he met when his car first broke down, and asks him, "Can you tell me what that noise I heard was last night?"

The monk replies, "I'm sorry, brother. I cannot tell you, for you are not a monk." The man accepts this. He thanks the monks for their graciousness, and goes about his way when he gets his car back.
3 years later, he is driving on another buisness trip. And wouldn't you know it, his car breaks down in front of the monastery again.

Again, he figures, he can stay the night. And, of course, the monks let him stay and offer him the same help as before.

And once again, during the night, he hears that noise. He has no idea what it could be. He decides to ask the monk once again, with hopes that he would trust him more this time around.
In the morning he meets the monk again, and asks, "I'm sorry for asking again, but what is that noise!?"

The monk replies, "I cannot tell you, for you are not a monk."

The man says, "Alright! I'll become a monk! What do I need to do!?"

The monk replies, "I need you to travel the world, and count every blade of grass if you truly wish to become a monk."

The man swiftly accepts and leaves all of his worldly possessions behind him to travel the world on this mission.

He goes to all corners of the globe counting grass blades.

After 50 years, he comes back to the monastery.
He gives the monk accurate numbers and the monks give him monk-hood.
And obviously, the first thing he wants to do is find out what that noise was. So he asks the head monk.

The head monk beckons him to follow him and he does.
After a few minutes of walking through corridors and rooms, they happen upon a wooden door.

The man can hear the noise. He gets excited. The head monk hands him a brass key.
He reaches with the key to the lock, and unlocks the door.

There is another door though. This time iron. And the monk hands him an iron key.

This happens again and again.
So many types of doors and keys. Every thing you could imagine. Glass doors, gold doors. Everything

Finally, they get to a door made of solid diamond. The noise is louder than ever. The monk hands the man the final key.

He opens the door and finally sees what has been making the noise.

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