I'm trying to learn Cantonese. I mention it because if you've ever dived into a new language, you know how tricky it can be. Cantonese is the most radically different language from English I've tried to learn. (I took French throughout grade school and high school; Latin was my language of choice in University.)
As tricky as it is to pick up tones and basic grammar of a language far removed from English, I can only imagine how hard it is to learn English, the ultimate mongrel tongue.
Unrelated: this article on productivity at Brain Pickings is making me rethink my previous thoughts on plodding vs. slumping. Although I write just about every day, I'm thinking it might be time to increase the frequency and duration. Work, Muse! Work!