Amy Morin knows more about mental strength than almost anyone on the planet — and she'll tell you the hard-won secret behind it: it started with loss. Amy is a licensed clinical social worker, psychotherapist, and international bestselling author of six books, including 13 Things Mentally Strong People Don't Do, which has sold over a million copies and been translated into more than 45 languages. Her newest book, The Mental Strength Playbook, hands you 50 science-backed "plays" for handling the moments that test you most at work — the anxiety spiral mid-negotiation, the coworker who wrecks your focus, the setback that knocks you sideways. Her...