title: AJAX activities disappear when browsing forward and back
body: <p>This is not a Meta question. </p>
  
  <p>I am trying to technically understand what principle is hidden behind the following behaviour. It's very easy to reproduce:</p>
  
  <ol>
  <li>Vote up/<s>down</s> anything on this page<sup>1</sup>,</li>
  <li>Click on any other link on this page,</li>
  <li>Come back by pressing the back button.</li>
  </ol>
  
  <p>Your upvote is not there anymore as well as any AJAX activities having appeared on the page.</p>
  
  <p>Why is that? Why is the browser acting like so? How could StackOverflow prevent that?</p>
  
  <hr>
  
  <p><sup>1</sup> If you are not connected, just wait for someone else's activity on the page (new comment, answer, vote) before moving page.</p>