The brain fog is hardest to describe. One symptom is that I confuse things much more easily now. It's like the resolution on concepts has gone way down. Instead of remembering a specific fact about a specific country (that I recently learned and resolved to commit to memory), for example, it's "some Middle Eastern country... or maybe it was African, but somewhere over there... did this thing where... something medical. Or maybe scientific." It makes socializing really hard. While using my multimeter recently, I convinced myself that voltage and resistance were the same thing, because they both fell into the "electrical" bucket in my brain. Even scarier, the double-checking mechanism failed, so that I didn't detect the absurdity for a while. It only resulted in a blown fuse, but I can imagine this kind of confusion having much more serious consequences.

As for physically, I just get winded much more easily -- and it's not the kind of winded I used to get, where if I pushed through, my body might complain but gear up to meet the challenge anyway. I just hit a brick wall where my heart and lungs won't give any more, either immediately or over the long run.

I've seen a mild improvement cognitively lately, though not sure why.