One of the most amazing things about World of Warcraft's addons is that you're always learning something new or adapting your interface to the new standards because you can build on top of what's already there. Sometimes you do the opposite -- take all of the information you've learned and processed but strip it all away and start from stratch. It's liberating to re-form your UI with years of potentially new and useful knowledge and expectations when going to build your legacy UI.
Magistrum sent me a screenshot for his mage's new UI. I looked at the picture first as I usually do when picking out a UI for the column and saw a very basic design that didn't jump out at me while being far from offensive. After reading the short email, it dawned on me that I was looking at this UI all wrong. This wasn't a first attempt at cleanliness with a new player, hitting the game for the first time. No, this was years of learning and understanding what makes your own personal UI yours. The little pieces are all in place where you want them.