For a long time - over 2000 posts - I have been putting blog entries into categories. The categories used to live in a long list on the right sidebar. I've taken them out of the sidebar, and now they're much less visible in the user interface to the point of being invisible unless you happen to search for them.
I have touched enough categories to not be authoritative on any of them. A good, tidy, modern blog that is comprehensive in some narrow sphere would have a tidy list of categories and would post in each of them regularly enough to be helpful. In contrast, a laundry list of one-time enthusiams just makes it pointedly clear when my interests have waxed and waned.
Another problem is that Typepad doesn't have a straightforward way to "pin" a blog post to the top of a category, the same way that it can mark a post to stay on top of the main page. That makes it trickier to create permanent navigation within a category.
I do hope to put together some better navigation, so that someone coming to the blog for the first time can read some more popular posts or ones that I like. The whole thing has long since gone from a narrow, coherent narrative and turned into an unpolished open notebook, gathering scraps from here and there and not always pieces that have an obvious relation to the work as a whole. If it were a real scrapbook it would have tape-tags sticking out of it at all angles in all colors flagging things that deserve to be seen again; that doesn't have to be done with categories.