Ben, In the World by Doris Lessing

At eighteen, Ben is in the world, but not of it. He is too large, too awkward, too inhumanly made. Now estranged from his family, he must find his own path in life. From London and the south of France to Brazil and the mountains of the Andes. Ben is tossed about in a tumultuous search for his people, a reason for his being. How the world receives him, and, he fares in it will horrify and captivate until the novel's dramatic finale.