[mattkrause]

This holds for natural languages too!

I did a linguistics degree as an undergrad, and one of the requirements was coursework/proficiency in two different foreign languages. Unless you planned on actually using both of them, you were strongly encouraged to choose very different languages, rather than (say) Spanish and Italian.

Having learnt a Romance language, I took a year of intensive Japanese (the tones in Chinese were a bridge too far). It was a nightmarish amount of memorization and I juste eked out a passing grade, but the exposure to totally different writing, grammatical, and honorific systems was also really fascinating.