Film history is often marked by seismic changes that seemingly come out of nowhere. Movies are just movies, and then a group of kids in the 1970s start making Jaws, The Godfather, Mean Streets, and Star Wars. Suddenly, movies are different. Then that’s the norm, a few decades pass, and another group of kids makes Clerks, Pulp Fiction, The Virgin Suicides, and Do the Right Thing . Movies are different again. Every generation has its shift. And we may have just had the next one. The past weekend, several incredible things happened in a theater near you. Top of the list is Backrooms , a modestly budgeted horror film based on a YouTube series, from a 20-year-old director, making over $80 million in its first three days. Movies don’t make $80 million on opening weekend without some sort of incredible set of circumstances, but Backrooms did. An audience raised on YouTube Shorts and TikTok memes saw one of the most famous coming to the movies, and they turned out in droves.…