I made a bunch of (mostly trivial) quality-of-life improvements to the design of my web site, mostly for visitors on mobile phones.
I also went through every single page, making them conform to the latest specifications of HTML and CSS (which mostly involved finding alternatives to obsolete elements, and fixing small syntax errors). Therefore, the Colophon page no longer lies when it claims that my web site conforms to these standards.
During this sort of janitorial work, I've discovered how much of the content on my site is old! I want to work on having more up-to-date content on my web site (i.e. content that more faithfully reflects my current interests and obsessions), and I don't want to cull too much old stuff, either, which means I have to expand.