我觉得你不用有挫败感，汉语本身很难，需要一点点来的。《欢乐颂》需要比较高水平的汉语学习者。你可以看汉语版的《天线宝宝》这种幼儿节目，这样接受容易一些。

Hi Chris, I started learning English at 6. I began watching American TV dramas since Junior high and watched over 20 of them during University days. I watched them for fun and with subtitles most of the time, my English gradually improved without me even noticing and I was told by native speakers that I sound pretty native. This is a slow process and the main idea is to get used to the tone and flow of the language. From my experience, except for some very old ones and those have many professional words (like the Big Bang Theory), most dramas are equally difficult to foreign ears. I guess the reason they categorize "欢乐颂“ as beginner friendly is because it includes lots of common daily conversation (which is great to start with!) Learning a language by watching TV drama is a great way but everyone has different need. You can either watch just for fun, enjoy the conversation flowing in the background, or watch a clip repeatedly until you understand every words they say. Chinese is a hard language, especially writing. As far as I can tell, you are already doing great in such a short period of time! So don't worry why you couldn't understand the so called 初学者应该明白. People say the "Friends" is English beginner friendly yet I still find interesting new expressions till today~

可以看懂电视剧应该已经达到C1的级别了，作为一名初学者，我觉得你可以明白一点点。3年以后？这取决于你花多少时间去练习中文。如果花的时间足够多，是可以的。