Well, that didn’t exactly happen. As I grew up, I was able to recognise the hetero Cool Girls in just about every stage of life I was in. In middle school, she’d play video games and watch South Park. In college, she’d down whiskey shots and discuss batting averages. As I entered my 20s and began dating more, I recognised that this "girl" was the type of woman most dudes seemed to go ga-ga over. Then, in 2014, with the release of the film adaptation of Gone Girl, the term "Cool Girl" entered into the millennial lexicon. As Gillian Flynn wrote in the novel, this is the type of "girl" who "smiles in a chagrined, loving manner and lets [her man] do whatever [he] wants." She is basically "the girl who likes every fucking thing he likes and doesn’t ever complain." Hearing the concept laid out so succinctly validated so many of my own insecurities about how I fell short of societal expectations of how a woman should make herself appealing to men (and judging by the barrage of smart reaction pieces about the Cool Girl that followed, many women on the internet felt the same way).