I thought this article was interesting. I will point out that a productive mathematician who is "only" spending 6 hours a day at the office may still be thinking about math in the background for several more hours a day.
Darwin Was a Slacker and You Should Be TooBY ALEX SOOJUNG-KIM PANG
Nautilus
MARCH 30, 2017
When you examine the lives of history’s most creative figures, you are immediately confronted with a paradox: They organize their lives around their work, but not their days.
Figures as different as Charles Dickens, Henri Poincaré, and Ingmar Bergman, working in disparate fields in different times, all shared a passion for their work, a terrific ambition to succeed, and an almost superhuman capacity to focus. Yet when you look closely at their daily lives, they only spent a few hours a day doing what we would recognize as their most important work. The rest of the time, they were hiking mountains, taking naps, going on walks with friends, or just sitting and thinking. Their creativity and productivity, in other words, were not the result of endless hours of toil. Their towering creative achievements result from modest “working” hours.
