One of the fundamental themes of The Alchemist is that our paths are pre-ordained or maktub, in the words of the shopkeeper.
The goal of life is to live in harmony with what is ordained for one, or one’s Personal Legend; happiness depends upon this harmony. Ostensibly, we all once knew, as children, what our Personal Legends were. The main problem is that as humans and adults, we strive to make things more complex than they really are.
In the text of The Alchemist, this problem is mirrored by the experience Santiago has with alchemy. While traveling through the desert with the Englishman, Santiago reads several books about the secrets of alchemy. The books claim that the original secret of alchemy could be written in a single sentence, but that mankind had made its explanations of that secret so convoluted that they could not be understood by anyone. Santiago rejects this and contends that he can learn everything he needs to know about alchemy through his day-to-day life. This conviction, that one’s fate, or Personal Legend, is apparent in any aspect of one’s normal life forms one of the most important themes of The Alchemist. When Melchizedek says, “When you want something, all the universe is conspiring to help you achieve it,” (22) he means that since it is fate that puts a desire in Santiago’s heart, fate won’t stop him from achieving it.
The problem is focusing one’s energy on determining what it is that one really wants. Santiago does this during the last leg of his journey with the Alchemist, when he learns from the desert to look inside himself and silence his petty fears. By silencing these fears, he is able to finally see that he is one with the world around him and that his Personal Legend is a harmonious part of that world. This is evinced in a magical fashion when Santiago is able to communicate with the elements, in the climactic scene in which he turns himself into the wind.