Once upon a time, a long time ago, there was an African man who lived in a small village. The village had, as many villages did in Africa, a witchdoctor who healed and protected the villagers with various incantations, rituals, and potions.
It just so happened that the man was having a little stroll when he heard laughing from far above him. It was the witchdoctor! He was flying and soaring and swooping, like a big bird of prey, and was having a grand old time.
After awhile the witchdoctor landed and saw the man. The man greeted him with the most astonished look on his face. "How... how... how in the world did you..."
The witchdoctor said, "How did I fly, you mean? Oh yes, it was a potion I've been working on. I drank it and became as light as a feather, able to go to and fro with the wind! It is a marvelous feeling, it is."
The man asked, "You did THAT, with a potion?"
The witchdoctor replied, "Yes, yes, it is very simple once you have all of the ingredients and you put them together juuuuuuuuust right."
The man asked, "Could you tell me and show me how to make this potion?"
The witchdoctor chuckled. "Sure, sure, let me tell you the recipe."
They spent most of the afternoon gathering all of the components of the flying potion. The witchdoctor insisted that the man do all of the work to make the potion because, well, the man was the one who wanted it.
The man listened intently to the witchdoctor as he gave him fairly complex instructions on how to assemble the potion. Finally, over a small boiling pot, the man had the last ingredient in his hand and was getting ready to throw it in. The witchdoctor stopped him and told him, "Now this is the most important part of the potion. You must not only do everything I've already told you, but you must also think in the way I've instructed, do you understand?"
"Yes," replied the man, impatiently.
"Now remember this. Whatever you do..."
"... DON'T THINK ABOUT MONKEYS"