I did the transition from Java to Groovy (because of Grails) which helped me to become familiar with closures and a more functional style of programming, which

I did the transition from Java to Groovy (because of Grails) which helped me to become familiar with closures and a more functional style of programming, which eventually got me interested in Clojure. I still think Groovy is valuable as a "better Java than Java" but it's kind of hard to explain to newcomers how much ahead Clojure is. It took me a while to leave my prejudices against the parens and try to understand why it was so powerful and why the LISP family of languages is still alive. It's not by mere coincidence.