Seems we as a species are getting close to "Peak Productivity". We've done all the obvious. Nowadays, we are so productive all the time that a lot of us are burning out from all the productivity. Seems you can't be 100% productive for a long period of time without getting fatigued. This article, 3 steps to start tackling your ‘productivity fatigue’, shows several steps for avoiding "Productivity Fatigue", aka burnout.