I got a job interview on Monday with a company that is using Clojure a really new functional language. So I need to prepare and in a short space of time. Now I could get all mixed up and want to read an entire book on the matter. I don’t believe this is the best way to learn. Real learn happens by DOING and no other way really. Koans are a great fun way to learn a new language, OK they won’t teach you the intricate in’s and out of the language, neither will they teach you the pro’s and con’ nor the real life use of the language but there are a great way to get you confident up and running, your knowledge of the syntax differences and the general feel of a language. The rest you can do later, yes, by reading book.