Read this https://code.google.com/p/tokland/wiki/RubyFunctionalProgram... and master it by refactoring some of the source code that you work on. Also follow up the references to work by Joe Armstrong and Rich Hickey. If there is anything there that is unclear, then google for pages that explain it in a non-Ruby context.
And read everything written by Uncle Bob starting with his books "Clean Code and "Clean Coder". He has a lot of blog articles out there as well as various conference videos. And he is also a Ruby developer in addition to C++ and Java.
Don't let the speed freaks drive you. Many of them are writing bad code fast. It is better to write clean maintainable code at a slower rate than it is to rush into things and create a complex unmaintainable mess. It is possible that some of the complex code that you have difficulty with is actually bad code and not something to emulate in your practice.
P.S. focus on learning Ruby not on Rails. Ruby is the basis for Rails but Rails is not the only Ruby game in town. Someday Rails will fade away but Ruby will still be going strong with new frameworks like Sinatra or Celluloid or Cramp.
And read everything written by Uncle Bob starting with his books "Clean Code and "Clean Coder". He has a lot of blog articles out there as well as various conference videos. And he is also a Ruby developer in addition to C++ and Java.
Learn and apply the SOLID principles http://blog.rubybestpractices.com/posts/gregory/055-issue-23... and maybe read some more of those Ruby Best Practices articles.
Don't let the speed freaks drive you. Many of them are writing bad code fast. It is better to write clean maintainable code at a slower rate than it is to rush into things and create a complex unmaintainable mess. It is possible that some of the complex code that you have difficulty with is actually bad code and not something to emulate in your practice.
P.S. focus on learning Ruby not on Rails. Ruby is the basis for Rails but Rails is not the only Ruby game in town. Someday Rails will fade away but Ruby will still be going strong with new frameworks like Sinatra or Celluloid or Cramp.