When she retired, Carole Howard took a surprising - some might call it radical - giant step out of her comfort zone. With little idea of what to expect, she overcame her usual risk-aversion and volunteered with her husband to be management consultants for a non-profit in Senegal, West Africa. The experience was so life-affirming they did it again the following year in Uganda. And then three more times after that, in Namibia, Thailand, and Ghana, each...