You still don't need to know anything about java to figure that one out.

I realize it's a contrived example, and I'm sure there exists an example where it would be critical to understand java to figure out what the deal is, but I haven't found it yet and I've been mucking in clojure for at least a year now.

I haven't worked with Java in a decade and it still bothers me that it has a NullPointerException when you can't actually manipulate pointers.