I think the biggest lesson that Santiago learns is a lesson about perseverance. His journey to find his treasure and Personal Legend is not easy. He has to deal with the harsh environmental dangers that are found in that region of the world, and he also has to deal with the human dangers. More than once Santiago is forced to deal with bandits that threaten to stop his journey. Santiago even debates giving up and returning home, yet he keeps pushing himself. He patiently perseveres despite constantly being impeded from obtaining his goal, because his goal is worth it, and that is an important lesson for Santiago and readers. Good things can come to those people who are patient and persevere through adversity.
Santiago also learns a great deal about spirituality and the natural world. He may have started his journey as a journey for wealth, but along the way he learns to search for and work toward a pure soul. If he wants to achieve his Personal Legend, Santiago has to learn to listen to and use the Soul of the World. Santiago achieves this harmony, and he learns that all of the world around him is different forms of the same spirit. This kind of knowledge helps Santiago learn and understand that he gained so much more from his journey than only material wealth.
Remember that wherever your heart is, there you will find your treasure.
In the novel, The Alchemist, by Paulo Coelho, Santiago learns a great many lessons. Santiago, a young shepherd, leaves his sheep to pursue his Personal Legend—the course of his destiny. He also learns to listen to the Language of the World.
The young boy, with the guidance of an old king, learns that there are omens everywhere, and that by paying attention to these omens, he will be able to learn what he is meant to accomplish during his life. This is his Personal Legend. When he goes on his dangerous trip across the desert, he finds more than one kind of treasure.
She smiled, and that was certainly an omen—the omen he had been awaiting, without even knowing he was, for all his life.
Santiago also learns to listen to nature, and watch for signs (omens) there: that in every aspect of the natural world, the earth is attempting to communicate its secrets if people will only listen.
The stranger continued to hold the sword at the boy's forehead. 'Why did you read the flight of the birds?'
'I read only what the birds wanted to tell me. They wanted to save the oasis.'
This novel is one that resonates with a great many people. It encourages the reader, through Santiago's story, to search for a meaning to one's own life. Santiago's life lessons can speak to people regardless of their "journey."