<p>The words &ldquo;yes&rdquo; and &ldquo;no&rdquo; get used in comparison to each other so often that it feels like they carry equal weight in conversation. In reality, they are not just opposite in meaning, but of entirely different magnitudes in commitment.</p><p>When you say no, you are only saying no to&nbsp;<em>one</em>&nbsp;option. When you say yes, you are saying no to&nbsp;<em>every other</em>&nbsp;option.</p><p>I like how the economist Tim Harford put it, &ldquo;Every time we say yes to a request, we are also saying no to anything else we might accomplish with the time.&rdquo;&nbsp;Once you have committed to something, you have already decided how that future block of time will be spent.</p><p>In other words, saying no saves you time in the future. Saying yes costs you time in the future. No is a form of time credit. You retain the ability to spend your future time however you want. Yes is a form of time debt. You have to pay back your commitment at some point.</p>