Insight problems involve thinking outside the box. This is where susceptibility to “distraction” can be of benefit. At off-peak times we are less focused, and may consider a broader range of information. This wider scope gives us access to more alternatives and diverse interpretations, thus fostering innovation and insight. Indeed, [the study] found that participants were more successful in solving insight problems when tested at their non-optimal times.

via Why You Need Boredom, Distraction, and Procrastination in Your Life.