Toward the end of The Alchemist by Paulo Coelho, the alchemist shows the boy how to make gold. They have stopped at a monastery and the alchemist melts lead in a pan, and adds a sliver from a "strange yellow egg." When the metal cools, the monk and the boy are amazed to see that it has turned to gold.
"Will I learn to do that someday?" the boy asked.
"This was my Personal Legend, not yours," the alchemist answered. "But I wanted to show you it is possible."
There are two things we learn from this brief exchange. First, the alchemist shows the boy that what he may have times thought was impossible is—in fact—possible. This could be seen as a form of encouragement for the boy as he has not yet realized his own Personal Legend.
The second thing we learn is that everyone's Personal Legend is different. The alchemist is telling the boy that he (the alchemist) has made his journey and achieved his Personal Legend. He has done his part and realized that which was meant to be for him. He is telling the boy that Santiago (the boy) must pursue his Personal Legend—not that of someone else. And he must continue on until he achieves that which he set out to achieve. His dreams cannot be the dreams of others, and there are no short cuts.
For the boy, finding his Personal Legend requires work, and the realization of his Personal Legend is unique only to him. He should not wish to follow another person's path to achieve that person's personal legend, but must find his own.