Hi, I had brain fog. Was staring at a calculator trying to figure out how to get it to work, knowing that I should be able to perform this task easily. Then, I was undertaking study, and had to ask the lecturer multiple times to repeat themselves, just because I knew the concept was important, but I couldn't process it. This was post radiation, but it could be just due to the whole cancer experience. It got better, another of the small improvements you can celebrate as a win in the days, weeks, months post treatment. Good luck xx