Unfortunately, the Zone is a fragile state. It will be shattered in an instant by its mortal enemy: distractions.

Distractions are the single biggest killer of productivity. They are more corrosive to your time and efficiency than any other force. They come in two forms, which we'll consider using the car analogy from the previous chapter:

  1. Interruptions. These are events that cause your car to suddenly grind to a halt. After the interruption is over, your acceleration begins again from zero.
  2. Mental Crowding. This is like adding extra weight to your car, which consistently reduces your acceleration and top speed.


Interruptions are blips of disturbance in your study time. They occur frequently and can be very short-lived. They will always rip you out of the Zone. Just a few seconds’ break in your attention is all that is needed to slow your car to zero. After that you will have to accelerate all over again.

Mental Crowding

Unlike interruptions, which are tangible breaks in your work, mental crowding is a more consistent, frictional force acting against your efficiency. This happens when your mind is occupied with thoughts and information other than your study.

Just as adding dead weight to your car will reduce its acceleration and top speed, mental dead weight puts a strain on your cognitive capacity and reduces your working efficiency.

The Real Killer

Most real-world distractions will involve both forms. Interruptions and mental crowding rarely appear alone, since one tends to lead to the other. Look at the final graph. The area under the triangles is your productivity with distractions. The area under the dotted line is your productivity without distractions.

The difference is huge. Most students grossly underestimate it. They believe that checking their phones for 10 seconds will only cost 10 seconds of productivity. They are horribly wrong.

Defend Yourself

The conclusion is obvious: distractions will ruin your productivity. You must defend yourself against them.

Interruptions cause immediate damage. This means that the best defence against them is to stop them from occurring at all.

Mental crowding is different. It’s very difficult to control which thoughts enter your mind, and it’s even more difficult to eject those thoughts at will. This means that the best defence against mental crowding is to learn how to minimise its effect rather than to hope that you can stop it from happening.

We will spend the next few chapters looking at the different types of real-world distraction and what you can do about them.