I've had my head firmly buried in Drupal for nearly two years now, and it's starting to show.  I've come a long way.  My starting point was "I have seen mentions of this software, I do not know what it does, but it might suit our needs."  Since then I've progressed to having built a multi-site install, managed by CVS—entirely on my own.  The development of my knowledge can be traced on my user account on drupal.org; my questions have slowly become more knowledgeable as I've fought my way—solo—through two very difficult conversions/migrations and a few others that were significantly easier.