For a non-believer, what good does realizing impermanence do?

Does a realization or just thorough understanding of impermanence, as it appears in Buddhism, benefit a non-believer in the rest of Buddhism, at all, especially not karma? I'm not asking if they can reach samadhi or be on the path, but if the effect of karma is really quite small and more a matter of character than empirical events, what good does an understanding of impermanence grant, in that sort of world?