If you are familiar with Scheme and Common Lisp, I would say not hard. Much easier than if you were a Java-only guy coming to Clojure I would imagine. (disclaim

If you are familiar with Scheme and Common Lisp, I would say not hard. Much easier than if you were a Java-only guy coming to Clojure I would imagine. (disclaimer: I'm only really a dabbler in any of them, but I found starting out in Clojure very comfortable after learning the crippled Scheme from SICP and enough Common Lisp from Practical Common Lisp, ANSI Common Lisp, and Land of Lisp...)