I was thinking about the fact that I spent quite a few hours reviewing my very rusty (30+ years old) university Russian language skills before my recent trip to St. Petersburg. I have even continued to spend a little time on it since I got back. Why? I probably won't spend much time in Russia in the near future, and even if I do, I could probably get by just fine with English, as most tourists do. There's very little chance of achieving fluency or even minimal competence at this point in my life, though I'm confident that I could do it if by some bizarre circumstances I ended up living in Russia for a while (I feel the same way about French and Japanese). Was it worth the effort for just a few brief interactions in Russian?
для человека "dlya chelovyeka" (for person) and человечества "chelovechestva" (mankind) are quite distinct, while "man" (with no a) and "mankind" are roughly synonyms. Russian also doesn't have articles (a vs. the), but the forms (cases) of nouns usually make the meaning clear.
I consider that sort of thing entertaining enough to buy books on subjects that interest me in other languages, as a stimulus to learn more of these odd bits. I don't buy as many as I used to do in French and Japanese, and I tend to buy children's books, since I am not very advanced. I found one cool one in St. Petersburg, a children's book called simply космос ("kosmos," space). I was disappointed that I couldn't find such a book with more focus on Russian spaceflight (it's a translation of a British book). But this turned out to be useful, since I was able to buy a cheap used copy of the English version on Amazon, greatly helping my study efforts.
Once a nerd, always a nerd? Yup.