Detached HEAD & the reflog safety net

$ git checkout HEAD~2

We check out an old commit directly. The HEAD label leaves main and sits on the commit by itself: detached HEAD.

$ echo "Tofu soup" > vegan.md
$ git add vegan.md
$ git commit -m "Try vegan menu"

Committing in detached HEAD works. Only HEAD moves with the new commit, and no branch follows it.

$ git switch main

We switch back to main. The experiment commit greys out: nothing points at it any more. It still exists, but it is hard to find.

$ git reflog

The flight recorder: every HEAD move, newest first. HEAD@{1} is our "Try vegan menu" commit.

$ git switch -c vegan HEAD@{1}

We create a branch at that reflog entry. The commit is saved, with a real name now.

$ git switch main

Now the second scare: back on main…

$ git reset --hard HEAD~2

…we reset two commits too far. "Add prices" and "Add desserts" disappear from main and grey out.

$ git reflog

The reflog still has them: HEAD@{1} is where main was right before the reset.

$ git reset --hard HEAD@{1}

We reset back to it and main is whole again. The same trick undoes a bad rebase, amend or merge.