What did Santiago learn at the end of the book The Alchemist by Paulo Coelho?

Santiago learns a lot of different things in
the closing pages of the book and all throughout the story. I think the one ongoing lesson
throughout the book is a lesson in perseverance. Santiago is continually met with obstacles that
force him to consider whether or not to go on in pursuit of his Personal Legend. Over and over
again, Santiago chooses to continue; however, he doesn't learn until the end of the book that
the actual journey was far more important than any supposed monetary treasure. This is what the
wind tells him at the end of the book.

"No," he
heard a voice on the wind say. "If I had told you, you wouldn't have seen the Pyramids.
They're beautiful, aren't they?"

Santiago also
learns that love is a far more important and beautiful treasure than any monetary and
materialistic treasure could be. It's why the book ends with him seeking out Fatima.

Finally, I also think that an important lesson that Santiago learns in the final third
of the book is about the value of possessing great treasures within. I think that treasure
relates to both perseverance and love, and the alchemist makes a point of telling Santiago how
valuable those internal treasures can be.

"To show
you one of life's simple lessons," the alchemist answered. "When you possess great
treasures within you, and try to tell others of them, seldom are you believed."