Drupal sites as LEGO bricks for the experience you build!
We all know how Drupal modules are the bricks you build your website with. Take it a step further and consider a "website" your building block for the bigger-picture architecture of your system. Now your blocks are all the Drupal distributions of all Drupal versions and you can use them together!
But wait! Dokuwiki or moodle or other systems can be building blocks too.
When you adopt the patterns of large systems like google or all of *.drupal.org, you can simplify your system to the extent that you can build and maintain an all-purpose community website with just students and volunteers.
This is a must if you are a student NGO, and a huge time saver if you run a bigger system professionally.
The technical and more advanced parts contain "single sign on", "theme building", "services", "distributions", "features"