Four years ago, David Letterman signed off his show for the last time, after 33 years that revolutionized late-night television. In this week’s “Sunday Sitdown,” Willie Geist chats with the iconic TV host about his relatively quiet lifestyle since leaving that role, the second season of his hit Netflix show "My Next Guest Needs No Introduction," and the state of comedy in today’s political climate. (Original broadcast date: May 19, 2019)