For the last 18 years, I’ve been leading film discussions at The Music Hall, a wonderful old theater in the heart of downtown Portsmouth, New Hampshire. Once or twice a month, I do some research on a movie that’s showing there and talk it over with a small group of film enthusiasts after the film has screened. I give a little background on the film–who directed, who wrote it, how it got made, etc.–and we talk it over. The Music Hall supplies the coffee and popcorn. I realized the other day that the process of familiarizing myself with a...