Simply Complex?

To Kill a Mockingbird by Harper Lee
This is a truly great novel. It's well-written, engrossing, poignant, and takes on a lot of the big issues. The difference is, it is comparatively up front about its issues, something many authors cannot do without keeping the story intact. It is at once complex yet simple to understand. I can see why it ranks so highly on the Radcliffe Top 100 Novels list. At the same time, I can also see why it doesn't even appear on the Modern Library's Top 100 Novels list. It doesn't have that sense of deep untertone and vast implications one often associates with great literature. So where do I stand on it? I respect Harper Lee's achievement in writing a true and important classic. At the same time, I often find myself more drawn to more challenging works. I'm glad I read it—I liked it—but it didn't give me that feeling of a mental workout that I enjoy.