All the people I ever admired and respected led balanced lives — studying hard, partying hard, as well as being involved in activities and getting a … - Cal Newport

if you keep interrupting your evening to check and respond to e-mail, or put aside a few hours after dinner to catch up on an approaching deadline, you’re robbing your directed attention centers of the uninterrupted rest they need for restoration. Even if these work dashes consume only a small amount of time, they prevent you from reaching the levels of deeper relaxation in which attention restoration can occur. Only the confidence that you’re done with work until the next day can convince your brain to downshift to the level where it can begin to recharge for the next day to follow. Put another way, trying to squeeze a little more work out of your evenings might reduce your effectiveness the next day enough that you end up getting less done than if you had instead respected a shutdown.

In an age of network tools, in other words, knowledge workers increasingly replace deep work with the shallow alternative — constantly sending and receiving e-mail messages like human network routers, with frequent breaks for quick hits of distraction. Larger efforts that would be well served by deep thinking, such as forming a new business strategy or writing an important grant application, get fragmented into distracted dashes that produce muted quality. To make matters worse for depth, there’s increasing evidence that this shift toward the shallow is not a choice that can be easily reversed. Spend enough time in a state of frenetic shallowness and you permanently reduce your capacity to perform deep work.

Shallow Work: Noncognitively demanding, logistical-style tasks, often performed while distracted. These efforts tend to not create much new value in the world and are easy to replicate.