A deeply original exploration of the power of spontaneity - an ancient Chinese ideal that cognitive scientists are only now beginning to understand - and why it is so essential to our well-being. Why is it always hard to fall asleep the night before an important meeting? Or be charming and relaxed on a first date? What is it about a politician who seems wooden or a comedian whose jokes fall flat or an athlete who chokes? In all of these cases, striving seems to backfire.