English is pretty hard to learn. There is no "economies of
scale" to speak of.
There is no guarantee when you see a similar word in future, it is
pronounced the same way.
There is no guarantee when you see a synonym in future, you can
recognize it.
There is no guarantee that when you see a word, you can understand
its meaning.
There is no guarantee when you speak to an audience, they
understand you. For example, I can understand British English
better than American English. It got so bad that I think I can
understand BBC News better than our own DJs talking. 
Amazingly .. these problems don't surface for chinese.
