"This is really important for everyone, and I bang on about it all the time with my kids. And my clients. If you don't write the task down in a list, those tasks lurk at the edge of the four or so slots of your working memory - I'm sounding very teacherish now - so this is valuable mental real estate. And it impacts your ability to do other focused work. So you always have these random to dos floating around as you're attempting to pay attention to your project that you're currently working on. If it's on a list, it's out of working memory."