" Jeff Weiner, the CEO of LinkedIn, for example, schedules up to two hours of blank space on his calendar every day. He divides them into thirty-minute increments, yet he schedules nothing. It is a simple practice he developed when back-to-back meetings left him with little time to process what was going on around him.4 At first it felt like an indulgence, a waste of time. But eventually he found it to be his single most valuable productivity tool. He sees it as the primary way he can ensure he is in charge of his own day, instead of being at the mercy of it. "
― Greg McKeown , Essentialism: The Disciplined Pursuit of Less