Analytical argument for the existence of a non-physical personal memory

Titus, have you ever seen this paper before?: https://pdfs.semanticscholar.org/e711/7f...43d450.pdf

It's about a patient with anterograde amnesia (page 358), which is supposed to prevent memory formation after the incident that led to amnesia, being able to still form long-term memories despite lacking access to them while awake. That the patient is clearly incapable of creating short-term memories and yet somehow manages to have long-term ones, antagonizes the idea that memory is merely a process of transition from one type to the other. But, more importantly, memory formation is clearly independent of recall, which makes the idea of accurately gauging memory "loss" based on the capacity of recall untenable.

Well, I didn't know the paper, but I had read about the phenomenon in question. 

Even without such concrete evidence, it seems obvious to me, from a purely logical point of view, that the failure to retrieve certain memories does not imply the absence of those memories (in one's memory bank).