There is a similar joke in Mony Python.

Not really - at least none that have been brought to my attention. A lot of Greek scholars were actually able to write, speak, and read Latin fluently. There are some inscription that we have trouble interpreting, but a lot of that comes down to translation issues rather than issues with the language itself. People can speak Latin fluently today - the Vatican uses Latin. I imagine any difficulties resulting from the complexities of the Latin language would cause problems for the Vatican or speakers of Latin today, and that's just not the case. In addition, if it caused miscommunications on any kind of a grandscale, the language probably would have refined itself to be comprehensible over time.

Of course, he is also talking about proper use of the language. If I were to say, "where is the book at?" you would know what I'm asking, even though it's not technically grammatically sound. So there's that to consider as well.