In today's world of disruptive change, three-year strategic plans have come into question. Companies whose strategies are celebrated in January are junked by March. The concept of dividing the process of strategy and execution just doesn't make sense anymore. In the era of the lean start-up, rapid prototyping, and agile product development, organizations must often act first and strategize later. How can leaders adapt to this world without losing their strategic minds—or worse, their shirts?