Retrograde amnesia targets your most recent memories first. The more severe the case, the farther back in time the memory loss extends. This pattern of destroying newer memories before older ones is called Ribot's law. It happens because the neural pathways of newer memories are not as strong as older ones that have been strengthened by years of retrieval. Retrograde amnesia usually follows damage to areas of the brain besides the hippocampus because long-term memories are stored in the synapses of different brain regions. For example, damage to Broca's area, which houses language information, would likely cause language-related memory loss.
With both anterograde and retrograde amnesia, it is important to understand that people's explicit, or episodic, memory is normally what's lost. Amnesia patients retain their personality and identity, along with their implicit, or procedural, memory. That's because your motor skills and instinctive physical memories -- like riding a bike -- are stored separately from your episodic memories. The hippocampus initially processes both types, but episodic memories move to the cortex, while procedural ones go to the cerebellum.
That's why Clive Wearing can still play the piano (implicit memory), but probably can't describe his first recital (explicit memory).
Read on to find out how people with huge holes in their memories carry on with their daily lives.