In Paulo Coelho's The Alchemist, an old man advises Santiago about the treasure he has long dreamed about, but the old man warns Santiago that if he promises what he does not have, his desire for it may wane. Let's look at this in more detail.

Santiago is a shepherd who dreams of finding treasure in Egypt, and he meet an old man who wants one-tenth of his sheep in return for information about the treasure. Santiago really does not want to give him one-tenth of the flock because he needs the money from them for his travels. That would be a sacrifice, so he offers one-tenth of the treasure instead.

The old man, however, does not want one-tenth of a treasure that might never be found. He is wise and practical, but he is not thinking only about himself. He tells Santiago that if he begins to give his treasure away, promising it to other people, his motivation will drop. The treasure will lose some of its potentiality and its appeal. It will not belong completely to him, and he will be working partly for someone else. He might not put in the same amount of work. Rather, he might start to slack a bit, knowing that he has to give up some of the treasure when he finds it. He should not give away what he does not have. He should deal in the present and strive toward the future.