Since having the strokes, I have enjoyed joking about some of the aspects of brain damage. It has been amusing (to me, at least) to jest that I don't remember names because of my brain damage, rather than the truth that I have simply forgotten. The ironic humor for me is that most listeners don't know if I am lying or not. I could be telling the truth, after all.
The month or so before I had the strokes is gone. I have no memory of it at all. In fact, I have repeated almost verbatim discussions of great urgency that came to the same conclusion, and were thereby resolved, in the weeks before the strokes. I know because I have the email chains. Conversely, if you are expecting me to respond to email you sent in September or October 2011, good luck with that; you are going to be waiting for a long time.
The joke is on me, though. Two and a half years on, and I suspect that my memory has taken damage. It may just be that the relative monotony of my life at the moment makes things harder to remember, or that I am simply getting older, but I don't think so.
In some circles of friends, my memory is notorious for being poor. That's always been amusing but slightly unfair: it is the indexing that has failed me; once triggered, the memory itself is clear and thorough. This experience is different, though.
I've found to my surprise that there are events, places and even people that I have no memory of at all. I was quite comfortable with the idea of a lost month or so: there is no way to magically encode the events that are gone into long-term memory. The prospect of not recalling things apparently at random is unsettling.
Memory is unreliable. That's why I chose to record how I felt on 9th September 2001 that day (TL;DR: I was there). I knew that my impressions of the day would change in the years since, but they're still there. That is the novel sense for me: memory that is not necessarily merely unreliable, but wholly absent.
It would be much easier if only boring things were consigned to the mental black hole, but that doesn't seem to be the case. Interesting people, places or events are susceptible, too. It may be that I lose things when I'm tired, or when I'm paying particular attention to something else, I don't know.
The best I can manage is to be consistent in my behavior. Happily I am less fickle than ever, so when I think I wouldn't have done something that I don't recall, the chances are I didn't do it. Of course, those may be times that brain damage is making me behave erratically, but nobody has said anything yet, so I shall continue to assume that my mentality is essentially unaltered.
I'm still going to claim brain damage whenever I don't know your name, though.