In a somewhat similar fashion, I often try to leave a failing test when I take a break. It makes it easy to get back into the code when you come back. You hav

In a somewhat similar fashion, I often try to leave a failing test when I take a break. It makes it easy to get back into the code when you come back. You have a well defined problem that is easy to inspect. You also have a feeling of a lack of closure. It's easier to think to yourself, "Well, I'll just get this code working" and once that happens you'll have gotten into the flow. If you leave all your tests passing, when you come back from your break you have to decide what's next and then push yourself over the energy hump to actually do it.