I think OP missed entirely the point of learning a new language. When I learn a new language, I try to use the language the way it was built to be used, instead of trying to adapt it to what I already know. That's why you'll often see me asking questions like: "What is the Rubyist way to solve this?". I do adapt the language, but only after I've tried their way first.
I started programming by learning C, which taught me how the computer 'thinks'. Oh, and the absolute basics of programming.
I learned C++, where I was firstly introduced to objects and reliable ways do handle resource allocations without leaks (hopefully :).
I learned Ruby, where I was firstly introduced to functional programming and a wonderful implementation of the language using objects. I also learned what expressive your code can be.
I learned JavaScript, which didn't teach me much, but I've used it extensively to practice what I had learned before. JavaScript does everything.
I learned Haskell, which taught me more functional programming, and how problems go away when you use the correct types (or containers).
I learned Scheme, which showed me how simple a language's syntax can be, while still effective. It confirmed what I knew all along: all those different syntaxes mostly don't matter.
Sure I could have learned all those things without learning a new language. But I had no idea they even existed. Now, what will I learn next? Any suggestions?