Writer vs. Autosave
This is from an old Hsu and Chan comic I found extremely funny and relatable at the the time, and still quote to this day.
Anyway, I had a moment like this a few weeks ago with The Swan May. I had been stuck on a particular scene for a VERY long time, and was finally beginning to push past it. I only lost about a paragraph and was able to reconstruct most of it, but I had a a great line that is lost forever now.