This is a great part to The Alchemist. The old man tells a story about a boy and a castle. The boy is told to walk around the castle with a spoon filled with oil. The boy is told to not drop any oil. The boy is successful in his task, but he doesn't remember any of the castle's grandeur. The boy is told to do the same thing again, but this time the boy is supposed to take in the beauty around him and not worry so much about the oil. The boy does as he is asked, and he is amazed at everything around him. Unfortunately, he spills all of the oil.
The point of the old man's story is that a man (or woman) can't enjoy the world around himself if he is completely focused on the job in front of him. Conversely, a man can't effectively complete an important job if he is too busy looking at everything else. The message is about balance and moderation. It's important to find a happy median between work and pleasure. The story is meant to remind Santiago that he shouldn't be so consumed with the end goal of finding his Personal Legend that he doesn't enjoy the actual journey. The story also serves to remind Santiago of his days as a shepherd. Enjoy the world around, but don't forget about the flock.
The idea is not unique to The Alchemist. Even Ferris Bueller reminds viewers that while he wants to go to college in order to get a good job, he knows it's important to have some fun along the way.
"Life moves pretty fast. If you don't stop and look around once in a while, you could miss it."
The point of Melchizedek's story is that “secret of happiness is to see all the marvels of the world, and never to forget the drops of oil on the spoon.” What he means is that when the boy in the story was first sent out to walk about the castle, he is warned not to spill a drop of oil from the spoon he carried with him. The boy was so paranoid about spilling the oil that he never saw the beauty of the castle or its riches. The second time the boy is sent out, he is told to make sure to pay attention to what is around him, while still carrying the spoon with drops of oil in it. Unfortunately, this time he got so caught up in the beauty and riches that he forgot about the oil, and it spilled. The point of the story is to find balance. Pay attention to what is going on around you, but don't forget to pay attention to what you are doing at the same time.