I would be pissed off about screenshots and notes about things to write stories about and stuff in my DF folder, but actual fortresses, meh. You don't get bored of them in a week or two anyway and start new ones?
I'm the same, except for two. For some reason I always find myself always coming back to Fishcrystals and Worthyboulder (currently, 20 and 12 years old, respectively). I can somehow always find new projects to keep doing (e.g. mining
every last piece of candy; a whole "castle setup", with city walls, inner battlements and a keep; draining large swaths of the magma sea; etc.), even if there are a few (real-life) months between them. In addition to those are all of my nostalgia forts (my first decent military, my first candy smithing, etc.).
Beyond forts, there are my key-bindings (which are very different from the defaults, though I guess it wouldn't be
too much work to recreate those; I play by feel, so I would have to just play and then realize what button isn't doing what it was supposed to), my worldgens (these
would be a pain to re-create, since I've put tons of time into tweaking them to be perfect for me), and my raws (not too many changes from the originals, but enough that I don't remember them all).
Although, the issue that spurred me into action was the fact that I'd have to do work to get things reconfigured, instead of just boot up and vent.