Then there's classical Chinese (wenyanwen).然后还有个文言文……

Forget it. Way too difficult. If you think that after three or four years of study you'll be breezing through Confucius and Mencius in the way third-year French students at a comparable level are reading Diderot and Voltaire, you're sadly mistaken. There are some westerners who can comfortably read classical Chinese, but most of them have a lot of gray hair or at least tenure.
放弃吧。太难了。如果你以为三四年学习之后你就能轻风般浏览过孔孟的文章,就好象差不多的三年级法文学习者能够阅读狄德罗和伏尔泰,哥你就杯具了。的确有一些西方人能够顺利地阅读古代中文,不过他们大都有灰白头发,或至少有教授地位……

Unfortunately, classical Chinese pops up everywhere, especially in Chinese paintings and character scrolls, and most people will assume anyone literate in Chinese can read it. It's truly embarrassing to be out at a Chinese restaurant, and someone asks you to translate some characters on a wall hanging.
不幸的是,中国古文到处出现,特别是在中国画和卷轴里。大部分人以为任何懂中文的人都能阅读它们。当你在中国餐馆,有人请你翻译一个屏风上的汉字时,那可真是让人无地自容。

"Hey, you speak Chinese. What does this scroll say?" You look up and see that the characters are written in wenyan, and in incomprehensible "grass-style" calligraphy to boot. It might as well be an EKG readout of a dying heart patient.
“嗨哥们,你不是懂中文么?这个卷帘上写的什么?”你抬头一看,发现写的是文言,还用的是无法理解的草书体……这样的书法就看起来濒死的心脏病人的心电图差不多。

"Uh, I can make out one or two of the characters, but I couldn't tell you what it says," you stammer. "I think it's about a phoenix or something."
“呃……我想我能看懂一两个字,但我没法告诉你它什么意思。”你结结巴巴地说,“我猜是关于凤凰之类的东西……”

"Oh, I thought you knew Chinese," says your friend, returning to their menu. Never mind that an honest-to-goodness Chinese person would also just scratch their head and shrug; the face that is lost is yours.
“噢,我以为你懂中文。”你朋友说道,然后继续看他们的菜单。即使那些字一个如假包换的中国人也会挠头不懂,丢的还是你的脸……

Whereas modern Mandarin is merely perversely hard, classical Chinese is deliberately impossible. Here's a secret that sinologists won't tell you: A passage in classical Chinese can be understood only if you already know what the passage says in the first place. This is because classical Chinese really consists of several centuries of esoteric anecdotes and in-jokes written in a kind of terse, miserly code for dissemination among a small, elite group of intellectually-inbred bookworms who already knew the whole literature backwards and forwards, anyway. An uninitiated westerner can no more be expected to understand such writing than Confucius himself, if transported to the present, could understand the entries in the "personal" section of the classified ads that say things like: "Hndsm. SWGM, 24, 160, sks BGM or WGM for gentle S&M, mod. bndg., some lthr., twosm or threesm ok, have own equip., wheels, 988-8752 lv. mssg. on ans. mach., no weirdos please."
现代汉语仅仅是古怪的难,而古典中文则是刻意让人不可能学会。汉学家不会告诉你这样一个小秘密:要看懂文言文一小段话,你必须首先知道它在讲什么。因为古典中文根本是由几个世纪的典故用一种简要的编码组成,流传于一个书虫们组成的精英小团体中,他们自己都彻底了解任何一点相关的文学背景。一个没有专业知识的西方人没法理解这些,就好象如果孔子本人来到现在,也看不懂分类广告中“个人”一栏里这类的东西:“Hndsm. SWGM, 24, 160, sks BGM or WGM for gentle S&M, mod. bndg., some lthr., twosm or threesm ok, have own equip., wheels, 988-8752 lv. mssg. on ans. mach., no weirdos please.”(译者注:这个意思就不翻译了,好孩子不需要知道……)

In fairness, it should be said that classical Chinese gets easier the more you attempt it. But then so does hitting a hole in one, or swimming the English channel in a straitjacket.
公平的讲,文言文你越尝试就会变得越容易。 不过高尔夫一杆进洞或者穿着束身衣横跨英吉利海峡也是如此。