I actually use HN frequently as a tool to concentrate better during work. I often juggle quite different tasks that I have to solve at work. To flush my mind and go from one finished thing to some completely unrelated next task, I jump to HN, read some things, then jump back to what I'm supposed to do. The important part is to have things actionable and with a definition of when they are 'done', so that you can close them and do the next task.