It depends a lot on how complicated your life is. I use parts of GTD, along with a to-do list and a synced calendar, but then I have a day job, two or three qua

It depends a lot on how complicated your life is. I use parts of GTD, along with a to-do list and a synced calendar, but then I have a day job, two or three quasi-entrepreneurial side projects, a house, pets, and a significant other. What having some kind of a written/electronic system does is that it frees you from having thoughts of "crap, that's another thing I need to remember to do" interrupting your creative work. When you have a thought like that, you should quickly get it out of your head and into a trusted system (your "outboard brain"). Then every so often (it has to be often enough that you learn to trust your system), you go back and look at your list and see what you can and/or must do. Slightly less often (GTD suggests weekly), you go through your projects and, in an organized way, ask "What am I missing?", and write the answers down. In short, once your life gets moderately complicated you'd be silly to try and keep all the stuff you have to do in your head. That's what computers and paper are for.