Paulo Coelho said this quote

The boy didn't know what a person's destiny was. It's what you have always wanted to accomplish. Everyone, when they are young, knows what their destiny is.At that point in their lives, everything is clear and everything is possible. They are not afraid to dream, and to yearn for everything they would like to see happen to them in their lives. But, as time passes, a mysterious force begins to convince them that it will be impossible for them to realize their destiny.