I don't know if you know this or not, but one of his favorite topics of humor was indeed Chappaquiddick itself. And he would ask people, "have you heard any new jokes about Chappaquiddick?" That is just the most amazing thing. It's not that he didn't feel remorse about the death of Mary Jo Kopechne, but that he still always saw the other side of everything and the ridiculous side of things, too.
That's such an amazing thing.
Ace has a good post about this.