As the son of a Brahmin, Siddhartha would naturally have enjoyed access to all of the finest lessons and things of life. Knowing of his natural superiority in many ways, he becomes disenchanted with teachers and his companions. In a burst of independence, he insists on being allowed to leave home to become a wandering Shramana (or Samana, depending on which translation you read). After three years or so, he tires of this as well. Near the end of that part of his life, Siddharta meets Gotama, the Buddha, and admires him greatly. But Siddharta continues to feel that teachers cannot convey the wisdom of what they know. Words are too fragile a vessel for that purpose. He sees a beautiful courtesan and asks her to teach him about love. Thus, Siddhartha begins his third quest for meaning by embracing the ordinary life that most people experience. Eventually, disgusted by this (and he does behave disgustingly), he tires of life. Then, he suddenly reconnects with the Universe, and decides to become a ferryman and learn from the river. In this fourth stage of his life, he comes to develop the wisdom to match the knowledge that direct experiences of the "good" and the "sensual" life have provided to him.
Few will find Siddhartha to be an attractive character until near the end of the book. Hesse is trying to portray his path towards balance and understanding by emphasizing Siddhartha's weaknesses and errors. But, these are mostly errors that all people fall into. Hesse wants us to see that we make too much of any given moment or event. The "all" in a timeless sense is what we should seek for.