Cool site, I've never tried Clojure before. My first reaction though is that (+ 1 1) is a highly unconventional and possibly confusing way of writing 1+1, and I'm not sure why that design choice came about.
The way to think about it is that you're processing a list, where the first argument is an operation, and the subsequent arguments are numbers to add. Clojure, and other Lisp based languages use this structure (a list) for representing everything - both data and functions. It turns out to be a very simple yet endlessly flexible and extensible concept.
On a lighter note, I use the same approach in understanding user needs as a product builder. I focus on letting people share the minutiae of their day rather than have them editorialize the big topics. By doing so, I get a lot of visceral insight and intuition.
Thanks for sharing this. I really enjoyed reading it.