It doesn't matter if it's 80/20, 90/10, 60/40 or whatever. The point is that a task consists of a two parts: 1. a small part of effort that produces most of th

It doesn't matter if it's 80/20, 90/10, 60/40 or whatever. The point is that a task consists of a two parts: 1. a small part of effort that produces most of the results 2. a large part of effort that produces what is needed to make #1 sufficient What explains number #2 is that people simplify their tasks in their heads. If you want to do task X then theoretically you only need to do X. But, in practice, you will have to do half a dozen other possibly smaller tasks as well which you have, while leisurely focusing on X, conveniently forgotten exactly until the point you actually start doing X. This applies to a surprisingly good number of various tasks, from programming tasks to even physical ones such as gardening.