"Keep It Simple, Stupid" is often an apt plan in life, not just in your technical endeavours. If something is complicated, it's easier to build badly, or break.. So I will place this "What I Learned Lately" post in the "general" section.
I was looking at the state of the technical back-end of my web site and blog (such as it is), trying to recall how it all fit together: what this or that file (or style) did and where it came from. Most of it is quite simple: the blogging "platform" itself is straightforward (a small CGI script called blosxom), the rest generally static. But I had included some bigger components, a so-called "framework" (Foundation), of which I was only using a tiny portion (barely noticeable really). Also extra fonts, mostly unused but cluttering up the HTML. When you add complexity like this, things can get slower and harder to extend. The final problem was: I barely understood what this extra stuff was or how it worked.
A final thing to note: testing the site to make sure it still worked and looked okay, I came across a lot of my old blog posts. Book reviews, some social comment, galleries and art. It all builds up and is fascinating to read now (to me at least). It's amazing to look back and recall I actually owned a Firefox Smartphone! Unfortunately it didn't work out for the long term. Things are a lot better now of course /s