The most difficult language is....

according to the British Foreign Office is Hungarian which has 35 cases (forms of a nouns according to whether it is subject, object, genitive, etc). Therefore knowing Hungarian means you have skill. Discuss.

I'm no native English speaker and I thought the language was very easy to learn when I started, but then, I was 10 then, and they say it's generally easy for kids to pick up new languages. I started French two years later and failed horribly, though.

As for Japanese, I think if you've actually sat down and learned the 2000 recommended Kanji, you've got the worst behind you. Japanese grammar is hella simple and I can see why they have trouble with a Western language like English that has DIFFERENT PAST TENSES.