Then learn Haskell. It's the most academic functional language and there's constantly new papers written pushing the frontiers of computer science. It's also one of the most pure functional languages, so if you can grok Haskell you'll "get" the functional style.

Some notes for learning Haskell. Start with 'Learn You a Haskell for Great Good' (http://learnyouahaskell.com/chapters). Then move on to 'Real World Haskell'. Then 'Write Yourself a Scheme in 48 Hours'.

Eventually you'll learn about Monads. They aren't as hard as most people claim. They're very abstract, and require you to think differently about things. There are plenty of great monad tutorials out there. Read one every night before you go to sleep. One day you'll wake up and it will all make sense.

The key for learning your first functional language is to forget everything you know about programming, and embrace the fact that you're starting from scratch. Otherwise "Returns" and using recursion instead of loops might trip you up. It's not "Hard", it's just different. If you're prepared, it's not a difficult journey, and you'll be a better programmer for it.