Does radiotherapy cause brain fog?

It's interesting. Cancer and looking at things through a different lens does often throw up a small problem - the normal we want to get back to isn't always particularly normal. Long hours, pressured deadlines - we become habituated to them until one small crack starts a bit of questioning. It's obviously terribly hard for people who can't do what they want and need to do because of cancer and treatment but it can be at least a bit disorienting when you question the habits of decades. It can also be a really good thing! Best wishes with finding your new normal.