I read this one a few years ago and it's just annoying me that I can't find any trace of it anywhere. I don't believe I've misremembered the details, but if someone can enlighten me:
The main character was a teenager about 18-20 years old and I'm convinced his name was Asfeo. He lived with his father who was very authoritarian and sent him away to spend time with a hermit/guru of some sort. The story took Asfeo into various situations where he had to surrender his will completely to the events that happened around him, this being the real crux of the story. So an early predicament was when we ended up in a lake and lost all of his possessions and needed to rely on what others, and the world, gave to him rather than relying on what he had brought with him. The climax of the story was of him arriving at a small house where the hermit lived, and needing to use the knowledge of what he had learned on his journey in order to gain access to it. After struggling to do this, he finally had his aha! moment and everything made sense to him. This is when the hermit appeared to him, and it turned out to be his father who was actually a wise old man who had sent his (possibly spoilt brat) son into the world to learn what life was really about, as he was preparing him for his legacy which was to be king or emperor or similar. In short, Asfeo needed a short, sharp lesson to gain some wisdom so he could live and rule appropriately - so it was a rite-of-passage book.