"The Mass isn't boring; you're boring!"

"The Mass isn't boring; you're boring! Guess what? If you're not paying attention and have no interest in anything that's going on, you're going to be bored. What a surprise! Think about your own boredom. Yes, you're boring."

-Tom Wilson (aka "Biff Tannen" from Back to the Future)

[Said in a light-hearted way (though making a serious point) in this episode of Catholic Answers Live ("The Healing Power of Laughter") in an interview with Patrick Coffin (starting about the 21:26 mark)]