This was sadly recent. I have git checkout aliased to ‘gco’.
I was on a dev branch with a load of uncommitted changes, and I accidentally ran ‘gco ..’ instead of ‘cd ..’ (I use them both quite often)

That was one of my more frantic google searches.....

Thankfully I was able to get all my changes back, but only thanks to IntelliJ’s local history feature allowing me to revert each file reload from disk.