As I sit in my apartment streaming the documentary, “Brat,” by Andrew McCarthy, I think this setup is all wrong. That’s because if you grew up in the ’80s, this group, their coming of age in cinema, is likely an inextricable part of your zeitgeist. As a memoirist, I often write about nostalgia, the careful dance of looking back on your life and trying to document it without an inherent bias. Don’t get me wrong, I loved watching movies from the ’80s. But in the end, this ’80s teen watched some great movies, developed some interesting crushes, and made my way in the world.