When you say "no" to most things, you leave room in your life to throw yourself completely into that rare thing that makes you say "HELL YEAH!" Every event you get invited to. Every request to start a new project. If you're not saying "HELL YEAH!" about it, say "no." We're all busy. We've all taken on too much. Saying yes to less is the way out.
-- Derek Sivers, Anything You Want, p. 12