Wer nicht hören will, muss fühlen
Wer nicht hören will, muss fühlen is a German proverb that literally means "He (or she) that will not hear (or listen) must feel".
Used in a punishment context, it is a direct reference to the painful consequences of disobedience. The phrase traditionally refers to feeling the effects of a spanking, and as such roughly corresponds to the English sayings "If you won't listen, you'll have to learn the hard way" and "applying the lesson to the other end." The German word hören has both the meanings of "to hear" and "to listen", and can also take on the implicit meaning of "to obey". The word muss (must) gives the act of punishment a compulsive note, and closely relates this proverb to Strafe muss sein.