In Walk Two Moons, why was everyone uneasy in Mr. Birkway's class?

Mr. Birkway, in Sal's words, is "mighty strange." He is not at all like a teacher is usually expected to be; he is flamboyant and over-the-top enthusiastic,

one of those energetic teachers who love(s) his subject half to death and leap(s) about the room dramatically, waving his arms and clutching his chest and whomping people on the back.

The students are uneasy in his class because they never know what to expect. Sal thinks that Mr. Birkway "might have a few squirrels in the attic of his brain."

Mr. Birkway is especially excited about journal-writing, and encourages his students to do exercises which will help them express their innermost thoughts and feelings. Unfortunately, in his undiluted fervor for the value of such writing, he allows himself to get carried away, unintentionally embarrassing and even hurting some of the children by reading their journals aloud. Although he takes precautions to make sure that he does not directly reveal the identity of the journals' authors, the students know immediately to whom each of the entries belong, to the mortification of the writers. It is only when Mr. Birkway himself is negatively affected by something written by one of the children that he understands how uncomfortable he has made everybody by his well-intentioned but inconsiderate actions. To his credit, once he realizes his mistake, he apologizes for what he has done and corrects his behavior (Chapter 13 and 32).