In the largest study ever undertaken on sexual fantasy, world-renowned psychotherapist and researcher Brett Kahr reveals the astonishing truths behind secrecy, shame, and taboo in this groundbreaking book based on surveys of 23,000 men and women from eighteen to ninety years of age. The definitive account of what our fantasies tell us about ourselves, Whos Been Sleeping in Your Head? overturns conventional wisdom about sexuality today.