The real sting here isn't about distraction itself—we know emails interrupt us—but rather Jacqueline Leo's precise measurement of the cost. Fifteen minutes suggests that regaining focus takes nearly as long as the interruption itself, a gap many of us dramatically underestimate when we glance at our inboxes "just quickly." If you check email six times a day, you've surrendered ninety minutes of quality thinking without consciously choosing to do so. It's the kind of arithmetic that makes morning writers and afternoon programmers suddenly understand why their best work requires ruthless email discipline, not just willpower.