Quote from Lilith in The Girl in the Plastic Bubble
Lilith: I'm going now. I'd like to leave a parting word. I want you to know that what I'm doing is very difficult. It is not to hurt Frasier. It's to acknowledge the fact that I'm changing. No one can go living year in and year out without ever changing. It's impossible. [looks at Norm and Cliff] Or at least it's very rare.