A line in a movie

My grandmother always said "be nice to the nice, ignore the bad, put light in front of night, make sure all your friends knows you love them, and be happy rather than serious" and all I know of it is that there's no point in it. The strong always win over the weak, so the only point there is, is to be strong.

He: That's how they make babies.
She: That's how they make murderers.