I imagine that you either had a prior knowledge of Java or that you had to learn it to be a better Clojure programmer?
I just realized you were referring to me specifically, as I mentioned in >>13 I have very little Clojure experience, and no Java experience. I've read a introductory book on Clojure, and read about the language, and listened to talks by the designer. I have a very limited perspective on the language, and so everything I say should be read with some suspicion, as it has been. I've just been trying to answer >>12, and responding to anything I can.