Ten years ago - even eight years ago - I would have responded exactly as you did; I was just as proud of my nearly-perfect memory as you appear to be. I could reel off long passages from books that I'd read years before (ones I liked, anyway) and I never needed an appointment book. Then, one fine day - more like over a period of a month, actually - my memory crashed and burned and died. I can't even begin to tell you what a painful and terrifying experience that is, every single waking minute for years afterwards, when that happens - and when you make your living by using your mind.
These days, I have a memory that works pretty well in some aspects, is rather poor in others, and is absolutely horrible in a a few. I still feel like screaming, regularly, when I reach for something I "know" I should have and hit a blank wall.
I don't know if this is a common experience for people who have good memories, but for your sake, I hope that my experience was an anomaly.
Update: In case you're curious, I'm 46, and lost my mind (?) at ~39. No serious drug or alcohol usage of any kind, no brain injuries, no physical reason for it at all. Had a relationship die a horrendous death that year, but that was about all.
Human history becomes more and more a race between education and catastrophe. -- HG Wells