Our “to-do” lists are usually hopelessly tangled:
“To do thing x needs thing y doing first but that can only be done with information that I must get by doing thing z”, and so on.
Suddenly that two-minute task is looking like half an hour, which is making our overall to-do list look gargantuan. Tackling tiny parts of tasks seems useless; tackling large tasks seems overwhelming. What a headache!
Getting Things Done (“GTD”, to its friends) shows us how to gather all our to-dos, and then use the quickest ways to break down a task (in reality, often a mini-project) into its constituent parts and which things can be done next, and what order to do them in (or defer, or delegate, or ditch).
In a nutshell: The GTD system aims to make all your tasks comprehensible and manageable, for stress-free productivity. No need to strategize everything every time; you have a system now, and always know where to begin.
And by popular accounts, it delivers—many put this book in the “life-changing” category.