I'm also looking to learn a Lisp, maybe Clojure, maybe some scheme. Clojure for me has a big drawback (and also an advantage) to run in a highly complex system

I'm also looking to learn a Lisp, maybe Clojure, maybe some scheme. Clojure for me has a big drawback (and also an advantage) to run in a highly complex system, at least as I perceive it, as I've never done anything in Java. What does one need to learn from Java world to program in Clojure? I understand perfectly what you say about the hacks with procedural languages. There's why I'm going for a functional language soon. Do you use a common SQL databse with Clojure or did you go the full route with Datomic? Do you use Clojure for desktop apps? For mobile apps? Or just back-end stuff?