From time to time, I end up in a state which I don't know how to recover from, and it's very frustrating to have to take an hour or two from my real work in order to try to figure out how to get out of that state.
The reflog is the failsafe. It is the tool that fixes all the scary states, as it keeps a journal of the states of each ref in the repo (like branch heads).
You can see where you were and hard reset back, no matter what state you are in.
https://roadrunnertwice.dreamwidth.org/596185.html