With writing---that's one of those "not applicable' things. One of the rare things to writing that's unique (though digital art challenges that). Basically any writing work can be reworked so long as it's been saved. Most writings aren't even considered "done"--ever. Even published works get changed, even short stories get changed and republished.

So for me.... only thing I regret losing is a large chunk of typewriter written papers that have gotten lost/scrambled over the years of frantic house jumping. Also, deleted files of older works I considered "defunct", at a time when I barely even knew anything about writing, and pretty much everything I wrote was defunct after a week. One story in particular, a post-apocalyptic story that starts with a man committing suicide by driving a muscle car into the side of bridge from the perspective of our character on the side of the road.