David Allen has thought a lot about organization and "getting things done." But I don't think it takes a lot of study to realize that our time and energy are limited so we should choose carefully how we spend them. I need to keep reminding myself of this.
Your work is going to fill a large part of your life, and the only way to be truly satisfied is to do what you believe is great work. The only way to do great work is to love what you do. ~Steve Jobs I love what I do