Fast forward to today and we know that nostalgia isn't fatal and we don't need a Z-pak to treat it. It's an outdated concept to consider nostalgia a malady, but it's not entirely untrue that the random, wistful affection for something is hitting hard right now in Hollywood. An academic once said that anything can trigger nostalgia — love, masturbation, landscape, even unusual food — but in 2018, it's something else: '90s headbands.