"Mother Nature" dictates this or that especially in reference to health stuff - so shall we all die and not treat medical conditions just because they are "natural?" It's annoying outside of that too e.g. I recently saw an article about colouring your hair "the colour Mother Nature chose for you is the one that best suits your skin tone so don't go more than two shades lighter/darker!" No one "chose" anything for you, dye your hair whatever colour you want
"Brain fog" - vague and overused, also (in context of "long COVID causes brain fog!" "brain fog is a symptom of menopause!" and so on) makes what is actually a form of brain damage sound harmless and normal