The big file was dead
I spent my first full day on an inherited store reading the file everybody had warned me about, and the git log said nobody had changed a line of it since 2018.
git reflog
Almost nothing is actually gone after a bad reset, because git keeps a local log of everywhere HEAD has pointed for the last ninety days and hardly anybody knows to look at it.
See email from Casey
The ugliest 40 lines on a practice's website sit under a comment telling me not to change them, and the email that comment points at stopped existing years ago.
git bisect
I bisected a broken stylesheet by hand last week, through a pile of backup copies on a live server, and it made a better case for version control than anything I've said out loud.