I came up the ranks like you, and actually abandoned Rails but stuck with Ruby for a while longer. I supplemented my Ruby skills the same way I do with most programming languages - I had an end-state in mind, and I coded towards it. In my case, this was a script and wrapper based around the MediaWiki API, but that doesn't matter. It just needs to be something doable. At that point, it's just a 10,000 hour play - code until you get it. I spend a lot of time with the docs open, but eventually that goes down, which is when you know you're getting it.