What is Drupal?
Drupal is the lackey that I force to write the boring, repetitive code (e.g., log in/log out, change password, database CRUD operations) so that I can focus on the interesting problems.
Before I came across Drupal, I was free-coding all my PHP and getting bored and frustrated doing it. System after system, I spent most of my time writing the same code (with minor variations) over and over. System after system, users wanted to change page content and it came to me in change requests. Drupal got me out of doing all that. It handles the grunt code for and it lets me turn content editing responsibility over to the site owners. With that stuff done for me, I can turn my time to more interesting and "value-added" aspects of the systems I build.