Up against a demanding tennis opponent in the last game of the set, you're connecting with the ball like never before, smoking it into the corners with precision and ease. You're halfway through a workshop you're teaching, and the participants, excited by your material, are peppering you with questions. Your answers surprise you—you hear yourself saying things that you didn't know you knew. Playing jazz piano with your trio, you feel like all three of you are mind readers. As your fingers improvise an edgy melody, the bass player and drummer stay right with you, anticipating and complementing your every move.

Got flow? When you do, everything falls into place. With in-the-moment total-focus ease, intent and execution merge: tennis balls go where you aim them, ideas and words appear out of nowhere, and jazzed collaborations take on a life of their own. Even if you're sweating like crazy and your heart is pounding out of your chest, everything feels so effortless. Is there a more blissed source of joy? Can't be. Which explains the frustration and cranked-up angst among flow aficionados—athletes, public speakers, creative performers—who've lost their magic touch.

As a psychotherapist specializing in hypnosis, I work at times with such elite performers—people who've spent long years learning and honing a skill that they can carry out with precision and grace. Except when they can't. Except when, with their mind and body out of sync, they lose…