“You know when you get a cinder from a barbecue right on the end of your nose,” Christopher Guest says as Corky St. Clair in Waiting For Guffman, explaining his choice to send burning newspapers through a small-town theater’s ventilation system to enhance his live production of Backdraft. He flinches, he winces, he minces. “You kind of make that face,” and then he makes that face, a face of surprise and discomfort, “you know, that's not a good thing.” Waiting For Guffman turns 25 this year. It’s a brilliant work of semi-improvised comedy, a classic, a stand-by, a movie I love and quote and laugh at every single time, and one that increasingly makes me kind of make that face.