The ancient Greeks had two different words for time: Chronos and Kairos. You could think of them as left-brain time and right-brain time. Chronos is the kind of time measured by clocks and calendars, by which we make appointments and set deadlines, and generally coordinate our activities with those of other people who aren't alongside us all day long. It's linear, it's sequential, it runs out. Chronos can be wasted by procrastination or indecision, maximized by efficiency, extended with a healthy lifestyle ... but nothing in the world stops it. It is relentless, bearing each of us onward from birth to inevitable death, with (sometimes it feels like) nothing but shoulds and musts, hurry up, and what might have been in between.