The condition is known as "brain fog". For example: https://www.healthline.com/h...

		swolchok on April 6, 2020 \| parent \| context \| favorite \| on: Ask HN: Do other people have days in which they're... The condition is known as "brain fog". For example: https://www.healthline.com/health/brain-fog#causes I've also seen common cold listed as a potential cause, which definitely jibes with my experience.