title: Is NaN falsy? Why NaN === false returns false
body: <ol>
  <li>Why <code>NaN === false</code> => false, isn't NaN falsy?</li>
  <li>Why <code>NaN === NaN</code> => false, but <code>!!NaN === !!NaN</code> => true</li>
  </ol>
  
  <p>I've been racking my brain trying to figure this out. </p>