title: Why do I need to use "rvm use default" after opening new terminal window?
body: <p>On opening a new terminal window (Mac OSX 10.7.2) and entering <code>rails</code>, I get the always fun 'rails is not currently installed..." message. But I enter <code>rvm use default 1.9.2</code> and all is good with the world.</p>
  
  <p>Where did I go wrong?</p>