Not Smart Enough !

Is there any "Smart Viewer" or "Not Smart Viewer" in Art as a Subject of View? Is Art in its general sense supposed to be understandable for everybody? Is there any responsibility for artist about the viewer and his/her understanding?
This week, which was filled with readings (because of midterm exams), was full of these questions for me. I was studying about Primitivism and the famous debate of 1984, oh Boy- (lets be feminist)-Oh Girl, it is amazing how every body could react to a thing which was a fact until yesterday and today there are some doubt about some parts of it? Oh wait a minute Art Theory is created this way, I believe. Maybe I'm just fed up with my readings and that's why anything can ridiculously amaze me!
Back to the first paragraph, I really didn't want to talk about the artist's responsibility but the viewer's understanding is the important point for me. As an Art History student I have experienced that when I learn about the history of a movement or a style, I actually can understand it better. Often I feel the piece better; the thing is that I think we first feel something and then later understand it, especially when the art piece is Abstract. Sometimes we even think art has nothing for understanding and it just expresses a feeling and we are lucky enough to just feel it. Well, many times a particular painting or sculpture meant to be that way -expressing a feeling- but not always. It is certainly important for studying the history or process of a movement (mostly Modern Movements). I believe that by knowing the history of a movement better you actually know (feeling and understanding) the art piece better. I don't know really how to connect these to the notion of a Smart Viewer but I don't like it when some easily say that oh, you are not smart enough to get it.