Letterman, Seriously: Dave's 10 Most Profound Moments
Warren Zevon on 'The Late Show with David Letterman.' CBS/Getty

Most people watch late-night talk shows to forget about their problems for a while. But during David Letterman's reign, the real world occasionally imposed itself on his show in unpredictable ways. Usually, the results made for hilarious comedy — other times, however, it might prompt Dave to become enraged, philosophical, mournful or even profound. Below are 10 of the most memorable moments when the Late Show got compellingly real.