What lessons does Santiago learn by working at the crystal shop?

Santiago learns that change is a constant. The merchant is grouchy and resists change, yet Santiago learns that change is needed if the merchant is to be successful. Santiago also learns not to put off what his goal is. The Merchant is a devout Muslim, and yet has never visited Mecca. Santiago knows he must continue his personal journey. Santiago learns the commerce of crystal and how to use language effectively. He also realizes that dreams do not always come true, especially if one waits too long.