One Saturday afternoon, my wife and I escaped to the movies. We had barely slipped into our seats and positioned the bucket of popcorn between us when a gaggle of teenagers jostled into the row behind us. They were having a great time together, noisily talking and teasing and laughing. During the previews, the conversation became even more animated as each kid weighed in on the merits of a coming attraction. Every so often I would turn around to dart a glance in their direction, a look I hoped would come across as a serious but not-too-parental appeal for theater courtesy. I was relieved when the opening credits of the feature finally started to roll and the group quieted down.