Getting things done in a much better way than just letting things happen, which often turns out not to be very cool at all.
David Allen
The older I get the more I resist the cultural zeitgeist of doing more with every waking day. Some of my most profound learnings have occurred while doing nothing. To get here I've read a whole lot of personal productivity literature. Getting Things Done by David Allen is my favorite.
"GTD—or 'Getting things done'—is a framework created by David Allen for organizing and tracking your tasks and projects. Its aim is a bit higher than just 'getting things done', though. (It should have been called 'Getting things done in a much better way than just letting things happen, which often turns out not to be very cool at all'.) Its aim is to make you have 100% trust in a system for collecting tasks, ideas, and projects—both vague things like 'invent greatest thing ever' and concrete things like 'call Ada 25 August to discuss conference schedule'. Everything!" - Erlend Hamberg
Allen's most liberating teaching is to learn to move ideas, big and small, to safe, sequestered spaces where you won't forget them, but they won't wake you at 3 AM, either.
Some take his teachings as gospel. There are workshops, seminars and apps that coach how to use the same multi-file system that he uses. To me this is counterproductive fealty. Hamberg agrees. He's written a simple distillation of a powerful perspective. Allen uses file cabinets. I use a few index cards.
Article: GTD in 15 minutes – A Pragmatic Guide to Getting Things Done