Ducky: I presume... the bad news is closer to home.
Gibbs: (referring to his father) There's no right way to be his son.
Ducky: Just as there is no right way for you to act as his father. The pain of watching a parent age is unlike any other. I vividly remember the first time my mother needed help brushing her hair.
Gibbs: It's backwards.
Ducky: Certainly feels like that. But in the end, well, it's simply life.