I understand it, I sound retarded when I try to speak it. So feel free -- although I'd probably dispute your notion of "fluent"
But in any case, Spanish is an Indo-European language just like Bulgarian -- from the Romance branch and not the Slavic branch, but it's the same general structure. For example, most Indo-European languages have synthetic verb systems (English is periphrasic but still somewhat synthetic, there's still an inflected past tense, etc). Finnish is agglutinative and has 15 noun cases whereas most Indo-European languages have but a handful, if at all. Finnish is SOV when most Indo-European languages are SVO, etc etc etc. To think naturally in this way requires some serious brain rewiring that would be very difficult to accomplish in one year.