Yeah, all the time. I had so many of those in a row that I began to be concerned - it was hard to function in daily life when I couldn't think straight. I badgered my neuro into giving me Aricept (5mg) which really helped. After three months, I got a little more function back, so I stopped taking it. I still have days when I'm too foggy to be coherent, but I try to rest up so that won't happen as often.
I get those days too. But it seems to last just one day at a time, thankfully. I can't seem to remember the names of people that I have known for years. It is quite embarressing!! And it just feels that you are "out of touch" with the world. It is hard to explain to anyone who hasn't had one of those days. Like your in a "fog". I do know what you are feeling!!
Lisa