On Monday night’s Conan, Bob Newhart reminisced about his dearly departed friend, Don Rickles — they and their wives were fast friends for five decades. Newhart recalled the first night he and his wife got to see Rickles perform live in Las Vegas. Even though Rickles was performing late-night in a casino lounge, while Newhart was performing in another casino’s mainstage, Rickles knew just how to level the playing field.

Newhart also told Conan O’Brien about how a joke thief — whom Newhart declined to name, even though the thief has died — changed Newhart’s career. He had thought about becoming a comedy writer and selling jokes, but decided after this to tell them all himself.