What did we find out that helps explains Chris' disappearance?

Chapter Eleven illuminates Chris' young years, and the things that made him turn away from his parent's lifestyle and materialism. His anger at his parents wasn't so much that they didn't work for what they had, but that he came to see their worldview in direct opposition to his own. Chris wanted to do without.... to help others..... to give back. His parents continually hassled him about his education, which would afford him more. He couldn't take the badgering, and maybe he didn't express his feelings to them the right way. Maybe his own actions made it impossible for him to get his point across.