As much as we'd love to live on caffeine and cortisol forever sprinting along at a manic, dopamine releasing pace, it's not good for us - & it's not sustainable.
I'm 32 and have stage 2 Adrenal Fatigue which in our Western Culture is almost a badge of type A honor: except it's really bad for us.
Whether we want to admit our need to break or not, our body's going to direct us to mindlessly troll Facebook, hop on words with friends, or justify an obsessively long trip to the bathroom mirror. The brain needs zone out time.