In Paulo Coelho's book, The Alchemist, the crystal merchant's explanation for not taking the pilgrimage to Mecca makes sense to the boy.
The crystal merchant, who has hired the boy in hopes of selling more crystal, describes what the Prophet teaches in the Koran.
The fifth obligation of every Muslim is a pilgrimage. We are obliged, at least once in our lives, to visit the holy city of Mecca.
The merchant shares that he never went on the pilgrimage because he could never trust his crystal in someone else's care. When the boy asks the merchant why he does not go now, after thirty years of working, the merchant explains that the idea of Mecca is what keeps him moving forward, that without the dream, he'd have no reason for living. He also notes that if he went to Mecca, he might be disappointed, so he just dreams about it instead.
As time goes by, and the boy earns more money, he dreams of getting his sheep back. That has become his new dream. The boy understands:
...because Egypt was now just as distant a dream for him as Mecca for the merchant.
In essence, both the crystal merchant and the boy have lost their hope and their faith in their dreams. It is because the boy has lost his dream of ever reaching Egypt that the merchant's reasons for not traveling to Mecca make sense to him.