I have been using Clojure for about 25% of my consulting work in the last 2 years, read two books on Clojure, and I had some Clojure examples in a book I wrote last year.
That said, I don't really feel "expert" at the language the way I do with Java, Ruby, and Common Lisp.
I am trying to fill in some gaps by carefully reading through one of my customer's Clojure code, and all Clojure libraries that I use like Noir, Compojure, etc. I am trying to pick up more idioms. I enjoy it when I see a new trick in someone else's code and going back to my code to improve it.