Most difficult programming explanation?

Question

Recently I tried to explain some poorly designed code to my project manager. All of the manager classes are singletons ("and that's why I can't easily change this") and the code uses event dispatching everywhere that a function call would have sufficed ("and that's why it's so hard to debug"). Sadly it just came out as a fumbling mess of English.Whats the most difficult thing you've had to convey to a non-technical person as a programmer? Did you find any analogies or ways of explaining that made it clearer?

Answer 1

When I was a programmer, I tried to use pictures and diagrams as much as possible to help my explanations. I do the same as a teacher now. After I got promoted to project manager,it helped to have been a programmer.