Your phrasing seemed to suggest you found mastering Spanish substantially easier even for someone with no prior knowledge of any of them.

Two years to master Russian is insane, though - unless you just went the immersion route and spent two years in Russia, I suppose, then two years would seem about right. But I know a fair few people who are doing Slavic languages in university, and even after four years I don't think they've quite mastered it, except a few who spend one or more of those four years in Russia... Those people do Polish and Russian both, of course, and obviously other subjects, but then I'm guessing you were doing other things during those two years as well, so, um, yeah. Insane.