What does Santiago learn?

At the start of Santiago's journey, after he has been robbed by a young man he trusted, Santiago reflects, "I'm like everyone else - I see the world in terms of what I would like to see happen, not what actually does." By the end of the story, he has learned the importance of being able to change. Change is at the heart of the story, as alchemy changes lead into gold. One of the themes of the book is evolution and the idea that when a person makes changes in his or her life, these changes affect everyone around the person. Everything is related to everything else. It could be argued that in some ways, Santiago is the alchemist in this story, because as he moves through his journey, he affects change in everyone he meets.