Ah, yes...this is my #1 complaint, my worst fear, the feeling that I've become brain-damaged and am losing a few more IQ points every day, or that my nervous system is deteriorating, or maybe a little of both.
Some days, talking to people in person is nearly impossible, as I tend to mispronounce words, use the wrong words, or generally slur entire sentences into a giant BLURBLHUMGLBB (for lack of a better...word?). Every sentence, every time. I sound like I'm either drunk or mentally disabled. I used to give speeches (not my favorite thing, mind you) back in high school, and I was never, ever this bad. Even typing this post is a stressful ordeal; I have to dig really, really deep for some of these words.
My typing and writing abilities are totally shot. Letters and numbers just don't want to come out like they're supposed to, and some days, my signature turns into a mass of squiggly lines, as though my hands and brain have forgotten how to write it...even though I do it EVERY DAY.
Reading is more and more difficult each day. Words just blend together, and I have to reread things several times in order to comprehend anything.
I took a computer programming class in high school, and used to write small amounts of program code in my spare time (up until about a year ago, actually), but now it seems I'm lucky if I can even remember what program code is. Routines that I wrote less than a year ago make little sense to me anymore. Basic math skills have all but disappeared as well; I commonly find myself using my fingers, when previously I could do it all in my head. This is especially frustrating at work, when I'm running a cash register.
My memory is totally shot...it took me almost an entire day to pack for my vacation last month, because I kept getting sidetracked, forgot what I was doing, or simply couldn't comprehend the idea of "packing." I'm amazed I didn't leave anything important behind.
So, in conclusion...yes. I know exactly what you're talking about.