I can't help but suspect that he has just a bit more awareness than he lets on. Not that he has any solid memories, but that at all times he can feel glimmers of recognition of things, but they're so faint as to barely be there. I say this primarily because he has no trouble remembering what a doctor is, can recognise his wife, and doesn't seem to be in a state of panic (as I would be if I found that I was in the middle of eating a meal and couldn't remember anything more than 30 seconds ago - meaning, didn't remember beginning to eat).

It seems like he must at least be aware that he has memory problems, even if he doesn't know much more than that. Perhaps he can sense those "older" memories slipping away as it happens, and thus has a constant reminder that he is losing his memories. Combined with retaining most basic knowledge (if he can remember how to play a piano, how to eat properly with cutlery, the concepts of dancing and kissing, Buckingham Palace, and what a doctor is, then he hasn't lost ingrained knowledge, just events), he would be able to hold on to an understanding that it is memory loss (not just losing memories, but knowing that it's called memory loss, and what that means).

It is practically impossible for any of us to really comprehend what his life is like. You try to imagine not having access to any of your memories, but in the very act of trying to do so, you invoke memories. His wife commented that it must be torture for him, yet he doesn't seem all that troubled. She is doing as we are doing - trying to imagine what it's like for him, by comparing it to how we have it. He has no memory of having long term memory, he has no base of reference for the comparison, and thus cannot really comprehend what he's losing.

True, but I was mostly comparing to an average memory than the case of that poor dude.