MostÈpeopleÈcarry debt for most of their adult lives. Yet, most books on debt focus mainly on how to pay it all off, and live forever without it. Too often, following that advice leads only to failure. People either give up, or pay off the wrong kinds of debt. They strand themselves with too little flexibility to survive a financial crisis -- and land in bankruptcy court. They neglect saving for retirement, homes, or college, and end up poorer than...