Those who stay long in privies forget how foul is the smell.

"The host, smiling, restrained his guest and said: Insects that live on smartweed forget how bitter it tastes; those who stay long in privies forget how foul is the smell. Here you listen to my good words and think them wicked, point to a slanderer of the Law and call him a sage, mistrust a correct teacher and take him for an evil priest. Your confusion is great indeed, and your offense anything but light. Listen to my explanation of how this confusion arose, and let us discuss the matter in detail."