Here is excerpt out The Alchemist by Paulo Coelho.
The shepherd asked the alchemist if there was anything that he still needed to know.
“No,” the alchemist answered. “What you still need to know is this: before a dream is realized, the Soul of the World tests everything that was learned along the way. It does this not because it is evil, but so that we can, in addition to realizing our dreams, master the lessons we’ve learned as we’ve moved toward that dream. That’s the point at which most people give up. It’s the point at which, as we say in the language of the desert, one “dies of thirst just when the palm tress have appeared on the horizon.”