I remember the days when I'd start with a blank text document in my Perl editor when the time came to design a website. Manually coding forms, validating, processing, writing SQL... it seems like a thing of the past. I really enjoy how Drupal takes care of database interaction and other technical details for you. It frees you up to actually design the website in a fraction of the time it did in the past.
I started using Drupal 5 in 2008, and I'm so glad that it's come so far in the subsequent years. I'm tempted to call Drupal a CMS, but isn't it so much more than that? Drupal's flexibility is absolutely amazing, and the ever-growing library of contributed modules saves us all from reinventing the wheel. If there's a functionality you need, I bet you can find it. Add in a few hooks of your own to customize the experience and it's good to go!
I have a stack of Drupal books that I've read cover-to-cover. Each time I read a new one, I learn so many new things and further refine my skills. I think back to my early days with Drupal when I was mercilessly cast into the scene by my job, and I'm amazed that I got by. The hacks, the in-page PHP, the core hacks! Oh gosh. Learning "the Drupal way" to do things over the years has saved me countless hours, has made my sites more secure and easier to upgrade.
I'm not finished learning yet, though. I'm never finished with learning.