The fact that a smart person is questioning and inquisitive gets under their skin.
What separates a smart person from a knowledgeable person is a smart person questions what it is they learn. They look at all the facets of what they have learned versus a knowledgeable person that simply regurgitates what they hear and read. When a smart person is in the face of knowledgeable people, the knowledgeable person gives this aura of distaste and frustration because the smart person can't just accept what they heard. The fact that a smart person is questioning and inquisitive gets under their skin.