I, too, once had a Russian pen pal; thank goodness she wrote in English. I took a lesson in Russian at a local community college but had trouble with that darn alphabet.
Once, flying home from Russia, I struck up a conversation with the American next to me, who told me that he was fluent in a number of languages. He noted that German was easy to pick up (he replied to a nearby passenger who spoke to him in German and I was suitably impressed). He said, though, that Russian was the most difficult language he ever attempted and he wondered if he would ever truly master it.
He further expressed a wonderment that such a primitive backward people could come up with an elegant, complicated and expressive language.
There wasn’t an alphabet until the missionary we know as St. Cyril furnished one. That not only facilitated evangelization, it opened up the literary world of Russian.