keep two to-do lists, one “open” and one “closed.” The open list is for everything that’s on your plate and will doubtless be nightmarishly long. Fortunately, it’s not your job to tackle it: instead, feed tasks from the open list to the closed one—that is, a list with a fixed number of entries, ten at most. The rule is that you can’t add a new task

We can think of time and space as our desktop, and the various ‘objects’ in our world (e.g. bananas, buildings, bodies) as symbols or icons on that desktop.