[gorjusborg]

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.

[steveklabnik]

If you like the reflog, you'll love jj's oplog: it's like the reflog, but for all repository state changes.