The first time I remember being truly struck emotionally by a piece of art was many years ago at the Metropolitan Museum of Art in NYC, long before I ever dreamt of being able to paint. I came across this 
Vincent Van Gogh painting, one of his Iris pieces. It seemed to literally vibrate on the wall. I was mesmerized, to the point of nausea and a throbbing headache that made me exit the room.
I often think about that experience, especially when I speak to high school or college classes where it seems they are more intent in their subject matter than in the way they express their emotions in the paint itself. This piece is a merely a group of irises in a pitcher, probably a subject painted through the ages by thousands of painters. Hardly anything earth-shaking there. But it’s in the paint and the strokes that the emotion burns through. The thick application of the background and the rich lines of the foliage all express much more than the mere subject. To me, this piece is brimming with desire and heartbreak, love and anger– a spectrum of human experience.
So I try to get kids to look beyond the subject and try to see what is really contained in the surface of any painting. After all, a pitcher of irises may say much more than it seems.
Redtree Times 
There is a lovely moment in Jodi Foster’s directorial debut, “Little Man Tate”. The titular character is looking at a Van Gogh of several purple irises and one white (or yellow?) one. Diane Weist’s character asks him, “Why do you think he painted only one white iris?” to which he responds “I don’t know. Maybe he was lonely?”
That may well have been the case, Tom.
I saw that movie years ago, whenever it came out, and remember that scene distinctly now that you mention it. How interesting that you remember it as well.