We would like to thank the many senior colleagues who shared their stories for their candor, mentorship, and insights. Within McKinsey Global Publishing, special thanks to Joyce Yoo for managing this ongoing project, to Steve Lackey and Myron Shurgan for their video-production expertise, and to Kareem Parrott, Shirley Shum, and Petra Vincent for the enhancements in web development. And thanks to everyone who provided collaboration and support, including Mike Borruso, Nancy Cohn, Torea Frey, Eleni Kostopoulos, Philip Mathew, Lucia Rahilly, and Nathan Wilson.