If you don't pay appropriate attention to what has your attention, it will take more of your attention than it deserves.
You don't actually do a project; you can only do action steps related to it. When enough of the right action steps have been taken, some situation will have been created that matches your initial picture of the outcome closely enough that you can call it "done.”
You can fool everyone else, but you can't fool your own mind.
Use your mind to think about things, rather than think of them. You want to be adding value as you think about projects and people, not simply reminding yourself they exist.
Anything that causes you to overreact or underreact can control you, and often does.
Getting Things Done summary
The author provides tips, techniques, and tricks for implementation of his workflow management plan, which has two basic components: capture all the things that need to get done into a workable, dependable system; and discipline oneself to make front-end decisions with an action plan for all inputs into that system. In short, do it (quickly), delegate it (appropriately), or defer it