If you’re like me, there’s a good chance you first came across the term “brain fog” sometime in 2020, when doctors told us that long COVID could cause a blend of memory loss, cognitive slowness, diminished focus, and mental fatigue. Psychologists weighed in, too, explaining that the dread of living through a once-a-century public-health nightmare could also cause one’s mind to stop working properly. But there were other potential reasons brain fog could befall you, too. Maybe you felt dim and dumb because you feared for your job, your asthmatic child, your immunocompromised parent. Maybe you were juggling your kid’s distance learning and your own remote work that, for most parents, felt like that medieval execution method in which one’s limbs are tied to four horses running in different directions. Whatever your flavor of pandemic agony, it was just too much, and the by-product of your illness or stress was a mind that glitched, slowed, went sluggish. Brain fog, we called it. For many of us, the fog never quite lifted.