What is Python 20th and final guideline
<p>Sometimes when my life needs some guiding light, I read the <strong><a href="http://www.python.org/dev/peps/pep-0020/">Zen of Python</a></strong> by Tim Peters and usually manage to get back on the tracks.</p>

<p>Today was one of those days, so I checked it again. I've noticed that the "abstract" section says:   </p>

<blockquote>
  <p>Long time Pythoneer Tim Peters succinctly channels the BDFL's guiding principles for Python's design into 20 aphorisms, only 19 of which have been written down.</p>
</blockquote>

<p>What would be this last unwritten aphorism?</p>
