In Dreams from My Father, what difficulties does Obama describe having as a child?

When Obama lived in Indonesia as a young child, he encountered the problem of trying to understand the violence and tragedy that he saw and heard around him. For example, he saw a man with a hole where his nose used to be come to his mother's door to ask for food. He also heard about the death of his friend's little brother and saw the despair of poor farmers waiting for the rains to arrive. He also witnessed an endless tide of beggars arriving at his door asking for help. 

Later, he came across a photo in Life magazine of a black man who attempted to peel off his skin. Obama described this moment as an "ambush attack" (page 51), as he never before realized the power of bigotry. Obama wondered if there were something wrong with himself, as he looked like the man in the photo. He also wondered if the people around him were delusional, because they didn't point out anything different about his looks.

When he attended Punahou, an elite private school in Hawaii, he felt isolated because he was one of very few black kids at the school. He spent his teenage years trying to figure out how to be a black man in America, as his father lived far away in Kenya and none of his white family members could guide him in this regard. He even found that his grandmother was afraid of black men, as much as she loved him, and this caused him a great deal of pain. His identity as a multiracial person caused him a great deal of distress in his youth because he felt isolated and unable to reconcile the black and white worlds he belonged to in Hawaii.