Clayton Christensen is an inspiring guy. Not only has he disrupted the business world throughout his career as one of the foremost innovation academics, he has also overcome a bout with cancer and a recent stroke. Introduced as "the Kobe Bryant of the innovation world," he kicked off the 2011 World Innovation Forum. He began by informing the audience of close to 1,000 that after his stroke one year ago, he had to relearn to speak one word at a time. He then went on to discuss some of the reasons good companies falter. He offered two particularly surprising explanations: