President Obama's father, Barack Obama Sr., married four times before he died. To this day, not all of his children have met one another.The seven surviving children are scattered from Kenya to China to the White House. The youngest of them has written a book about his life in Kenya — and the life he describes is altogether different from that of his half-brother, the U.S. president.At the very least, George Obama's memoir answers the perennial question: Why can't you be more like your brother?Riding Around 'The Ghetto'On a recent afternoon in Nairobi, George Obama is slouched way down in...