10. Mueller is often described in serious terms, but he isn’t without a sense of humor. In 2013, at a farewell event to celebrate his public service — at which one person joked he would “depart Justice for the last time, hopefully” — the remarks at times were reminiscent of a roast, and Mueller not only laughed along but took part. During his 8½-minute speech, Mueller told a story about a particularly tense senior staff meeting, where he admitted he was a “wee bit ill-tempered.” Mueller’s chief of staff, Lee Rawls, out of the blue asked, “What is the difference between the director of the FBI and a 4-year-old child?” The room grew hushed, and Rawls delivered the ice-breaker: “Height.”