Chagigah 22 - Enmity of the ignorant
People who are knowledgeable (called "chaverim," or trusted friends) are subject to less regulations than the ignorant (called "am haaretz," or the "people of the land.") For example, the additional precautions regarding purifying vessels in a mikveh apply only to the ignorant. However, this does not go well with the ignorant, and causes their enmity toward the learned.
Here is an example. Holy objects are accepted for sacrifice from the ignorant, in the hope that they did prepare them in purity. However, the priest's portion, "terumah" is not accepted by the knowledgeable priests, because perhaps the ignorant made it impure by mistake, and it would be forbidden to eat it. This seems illogical. If anything, we should not believe the ignorant about the priest's portion, which is less strict, and not on sacrifices!
Look at consequences though. If a knowledgeable priest refuses to accept a portion from an ignorant, then the ignorant will be upset, but at worst he will now go and give his unrequited portion to his ignorant friend priest. However, if the priests do not accept his items for sacrifices, he may go and build himself another Temple - therefore, they accept his oil and wine, presuming them to be pure.
Rabbi Yehoshua could not understand some of the opinions of Beit Shammai regarding ritual purity, and he exclaimed, "You should be ashamed of yourself, the (already dead) Sages of Beit Shammai!" One of the students explained to him the reason related above, about ignorant people not accepting that their utensil were impure, and thus elucidated the logic." As a result, Rabbi Yehoshua fasted many days, until his teeth blackened, since he has offended the memory of the Sages wrongly, and Beit Hillel changed their rulings to agree with those of Beit Shammai."
Art: A Barn Interior With A Still Life Of Kitchen Utensils And An Owl, Two Men Beside A Fire Beyond By David The Younger Ryckaert