Branches are just pointers into a graph of commits. The graph cannot be mutated (it can be pruned by garbage collection but that does never happen related to an

Branches are just pointers into a graph of commits. The graph cannot be mutated (it can be pruned by garbage collection but that does never happen related to an oh shit event, it takes weeks even in a heavily modified repo). The pointers can be modified to point anywhere else in the graph, which makes things look mutated without being mutated. Using reflog you can get your back to where your pointers pointed to at any earlier point of time.