Glymphatic. I stumbled over the term glymphatic system last week and briefly had to pause. The concept is now widely used and feels intuitive, but it did not exist when I was in medical school. The term was only introduced in 2012 to describe a glia-dependent, perivascular clearance pathway in the brain. And yet, everything it refers to, including perivascular spaces, astrocyte endfeet, cerebrospinal fluid flow, interstitial clearance, was already in the textbooks. All the parts were familiar to me, but the label was new. That moment of confusion stayed with me: neuroscience moves forward not just through data, but also through names.