Well, I have barely worked with Drupal/Joomla/other or Magento/Prestashop or even PHP in general, and I've always thought it would be quite boring after the first CRM/e-Commerce site, as you said, to put together some plugins and glue-code, some customizations and few more...
On the other side, I've worked extensively with Java, and on a lesser extent with Scala, C++, C# and other languages, Unity3D, etc on projects which have little to do with CRMs.
Perhaps you're not bored of working with computer, just worked of the reiteration of the same project with little variations and the technology you're using...
Try something different!