<p> Q: How did I not know about this? A: You never read the manual.</p> <p> (A close friend of mine from college with whom I&#39;ve worked professionally now and again, once suggested that the secret to our individual successes was that we were the ones willing to read the manuals. Obviously in this instance I failed.)</p> <p> Oh, good lord, the number of times I&#39;ve done <code class="verbatim">M-x UP RETURN RETURN</code> to re-do <code class="verbatim">query-replace</code> on a new buffer, when I could have just done <code class="verbatim">C-x ESC ESC (repeat-complex-command)</code>.</p>