Tchaikovsky disliked teaching at the best of times, but he particularly didn’t enjoy teaching female students, most of whom, in this period of history, were of an amateur status:

Although it is a dreary business to have been forced to explain to my young men’s classes for eleven consecutive years what a triad consists of, at least I have had the consolation of feeling that I am ramming essential knowledge into them because they intend to take it up music as a profession.  But the young women’s classes!  Heaven’s above!  Out of sixty or seventy only five at the most will ever make musicians.  The rest come to the Conservatoire to fill in time or from motives which have nothing to do with music.  They are not less intelligent or less hard-working than the men, rather the opposite … but they all come to grief the moment they are unable to apply a rule mechanically or use it by rote.  I often lose patience with them – and my head – and go quite frantic with rage. 

A. N. Levitskaya-Amfiteatrova described, “He was handsome but very stern and the expression on his face was of almost constant displeasure.  When he came into the classroom he looked sombrely at us under eyebrows drawn into a frown and answered the students’ greeting with a barely noticeable nod of the head.”

Cited in: Hanson, Lawrence and Elisabeth (1965) Tchaikovsky: A New Study of the Man and His Music.  London: Cassell & Company, p.147.