An excerpt from Warrior of the Light by Paulo Coelho (Page 10):
"A Warrior of the Light knows that certain moments repeat themselves.
He often finds himself faced by the same problems and situations, and seeing these difficult situations return, he grows depressed, thinking that he is incapable of making any progress in life.
'I've been through all this before,' he says to his heart.
'Yes, you have been through all this before,' replies his heart. 'But you have never been beyond it.'
Then the Warrior realizes that these repeated experiences have but one aim: to teach him what he does not learn."
If you enjoyed the preceding passage you will likely enjoy reading the books Warrior of the Light and The Alchemist by Paulo Coelho.