Once, long ago, as a teenager on the shores of Lake Erie, I asked a friend what he was planning to do for the summer. "I'm doing nothing", he replied. "Sometimes it's really important to do nothing." I still remember his response, though within hours I would have turned his homemade sailboat upside down in a sudden crosswind. Years later, I would realize I had followed his earlier advice to the letter, and it may have saved my life.