This is awesome. If you've learned to write object-oriented code (abreviated OO or OOC) in the last 20 years you may have started by learning Java. Object oriented code is objects for a reason, and objects are big piles of code people have written that do things. Math, languages, graphics, these all happen on computers for a reason, because someone wrote the code to it. Well Java, is a programming language made up of piles and piles of code. Everything from the low-level programming to interact with hardware to advanced accounting operations is a lot of already written tested and working code that can even do taxes in one click. That's a lot of code while you're learning to program. Plus it can do anything.
Enter this article on frameworks ^^
Why this is awesome is because Drupal is a factory of factory of factories waiting to happen that a Drupaler (or you) can use to build sites, similar to the ideal world pictured in the article. I laugh now because he was right, even in 2005. Less common is learning Java today with python's OO capabilities but it's still out there getting taught for sure. Drupal is built in PHP and not Java, it doesn't work almost anywhere like Java does. Okay, Drupal is a factory of factory of factories that make websites. If you're here, you've probably seen ads that say Java is on over 3 gazillion devices; PHP might be only on billions of webservers and doesn't care about hardware since it's for making websites. A programming language is a programming language and we've got it good with this open-source PHP and Drupal, it is a factory of factory of factories.