Art History Intresting yet frustrating

So I am an art history minor and I took AP art history in high school and loved it! Then I had the opportunity to study abroad and study art history in Italy in front of the actual art! Learning about all the details and the time period and how it influenced the different art absolutely fascinated me. In Italy we concentrated mostly on Renaissance art not really the modern art side. Well I am taking post impressionism to surrealism this semester because I've never really understood modern art and thought I would appreciate it more if I understood it better. There is some truth to this statement I do appreciate some Balla, Klimt, and Cezanne more but at the same time I feel like we come up with analysis out of the blue. Modern art can be frustrating! Today in class we spent 25 minutes talking about a black square. a BLACK SQUARE! I was so bored!, While some of the debates about religious meanings were interesting I felt like we were killing that poor black square. I went from appreciating it more than I normally would to despising the stupid black square and its ambiguous meaning. I understand there is no real definition of what art is but I don't understand why we have to talk a painting to death its frustrating!