Suppose you write all task down and you have the task list in front of you. How can you choose one task to do next?

33% of people, even if they have the task list, can not choose one task. Decision making of what to do is difficult than we think.

In the processing phase of GTD, we put all the items of concern into the box, and then we process one thing at a time from the top of the box without considering urgency. The way of processing is very similar to the way of learning told in (1.3.4) Learn from one end: if you do not know where things you need are, all you can do is learn from one end.

In those approaches, we are assuming all things have equal priority and abandon the decision making.

The concern of this method is that it takes much time to complete. Allen says it is ideal to secure two days. Also, he says, it can take more than 6 hours to collect, it can take an additional 8 hours to process. In many cases of yours, your gathering and processing are interrupted. However, the state that all information is gathered is much better than the state that all information is only in your brain. Even if you are interrupted, the contents of the inbox remain as they are. You can continue your work after.