In the first episode of “Buffy the Vampire Slayer” (Welcome to Hellmouth), Buffy learns that she has supernatural powers that allow her to fight vampires, demons, and a whole host of otherworldly creatures. The first time I watched this episode, I was 10 years old. My mom and I used to sprawl out on the couch and watch episode after episode until one of us eventually fell asleep. Now, a decade later, I’m about four readings behind and haven’t started studying for my midterms yet, but thinking maybe I should rewatch an episode of “Buffy.” 10 episodes later, I’m deep in the Wikipedia page, reading the backstory behind the characters, subplots, and motivations. ..