Wonderful post. I just finished reading The Undoing Project, and one thing that struck me was that Amos Tversky almost never responded to any request right away. So I agree with your idea of letting it sit, at least overnight, before saying either yes or no. Also, it’s important to determine if you’re saying no to something because it’s outside your comfort zone (not a good reason to say no), or because it distracts you from doing what’s important (which is a good reason.)