For Chinese people who try to learn English, one of the hurdles is building up vocabulary.
I still remember vividly how I used to spend hours and hours trying to memorize every single word in the TOFEL vocabulary book before taking the exam.
During the time, I was really amazed by what my brain could do. Sometime, when my friends tried to test me by randomly picking a word and asking me to spell it, I could tell them where exactly the word was in the book, which page and which line, but of course, the only thing I could not remember was how to spell it.