We're living in a very auspicious time in human history, considered by economists to be the golden age of mankind. The number of millionaires and billionaires in the world has grown steadily in recent years, many of them starting from almost nothing. Yet this millionaire population represents only around 1% of the world's population. The other 99% make up the middle class and the so-called poor. Why this huge difference? What have these millionaires...