We explore the centrality of the practice of "not knowing," that helps us to move from ordinary knowing to extraordinary knowing. We examine both the obvious value of many kinds of knowing and the shadow side of knowing, including its habitual and often addictive nature. Then we look at three ways of practicing not knowing: (1) in our mindfulness practice; (2) in listening to others as a practice; and (3) in being with transitional periods in our lives, when some important aspect of our lives remains unresolved.