You have a finite amount of willpower that becomes depleted as you use it. Your will, in other words, is not a manifestation of your character that you can deploy without limit; it’s instead like a muscle that tires. This is why the subjects in the Hofmann and Baumeister study had such a hard time fighting desires — over time these distractions drained their finite pool of willpower until they could no longer resist. The same will happen to you, regardless of your intentions — unless, that is, you’re smart about your habits.

No one owes you a great career, it argues; you

With these rough categorizations established, the strategy works as follows: Schedule in advance when you’ll use the Internet, and then avoid it altogether outside these times. I suggest that you keep a notepad near your computer at work. On this pad, record the next time you’re allowed to use the Internet. Until you arrive at that time, absolutely no network connectivity is allowed — no matter how tempting.