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.

As email spread through the professional world in the 1980s and 1990s it introduced something novel: low-friction communication at scale. With this new tool, the cost in terms of time and social capital to communicate with anyone related to your job plummeted from significant to almost nothing. As the writer Chris Anderson notes in his 2009 book, Free, the dynamics of reducing a cost to zero can be “deeply mysterious,

the crucial step in programming is not the actual act of mechanically typing commands into a computer, but instead crafting the underlying solution that is then translated into code.