This is probably the best article I have ever read as to why it is difficult. I would recommend it:
http://pinyin.info/readings/texts/moser.htmlYou will not find an answer to Chinese fluency - especially not to the degree of being 'bi-lingual' - by purusing a few books or films. This may sound discouraging, but you need to be willing to put in many, many years of consistent (important, or you will begin to forget things) effort to become skilled at the language. Ideally, formal study beginning with simplified Chinese is your best bet, while juggling forms of self-study and spending a lot of time around native speakers. Traditional Chinese is much easier if you have simplified reference points which are modelled on their traditional variants, especially since comparatively few people actually write using traditional Chinese on tje Chinese services like Renren, Weibo, Sina, QQ etc. which you should be purusing (very often, to seek out and spend time interacting and practising with Chinese people; there are lots of people here willing to learn English, and finding language partners should take only confidence and consistency).
If you have other questions, feel free to post them and I will try to help.
This post was edited by Madotsuki on Jun 8 2014 04:32am