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 time for two months.

Her adventure was simultaneously an outward journey (of miles and cultures) and an inward journey (of...