What does Becky say?

What does Becky say after the soldier tells her that his grandfather who had committed suicide had said "just because a man may leave the table in the middle of dinner doesn't mean he didn't like the food" and she says "that's supposed to mean something...? ...all that means is that [?]" ...what's the end of that sentence? "...insanity is (something)"...?
No subtitles on the DVD.