[westiseast]

It's my personal experience. I don't really know how you quantify a language as being 10x as hard? Do you need to be 10x more clever or work 10x more? The American foreign diplomat service routinely trains its staff to relative fluency in a couple of years.

As with my other comments, taking Chinese as a whole it is difficult, but breaking it down into components, some parts are crazy hard and parts are quite easy. I think once you get past the hump of becoming used to tones and some of the initial grammar weirdness (for English speakers) then there aren't many grammar complexities, vocabulary is very repetitive and even poor pronunciation isn't as big a deal as you think - witness Mark making lots of tone errors but being understood quite well.