An everyday description of feeling muddled and cognitively slower than expected - normal really - but which following COVID has put on the clothes of medical parlance and has become one of the classic, "I feel it, so it is" non-sequiturs.
In reality, most of us are objectively less clever and sharp than we think, particularly as we age, or get promoted beyond our abilities. That's life, and there's plenty of evidence it's normal. But post 2020, as COVID brain fog exploded, unchallenged. Brain fog can now follow any unpleasant event outside our control, particularly when someone else might be to blame (workplace accident, illness, trauma). Post 2020, it is an unchallengeable pseudomedical term that describes the gap between what we want and the reality of what we are in a harsh and difficult world. Brain fog is perfect weather to hide in!
Co-worker (1): "I need the afternoon off, my brain fog is particularly bad today. I'm so tired I've left the banana on top of the what do you call it. I've never been the same since COVID"
Co-worker (2): ".... better keep my lips sealed - don't want to make her brain fog worse by inflicting a hate crime..."