Listening to an hour and a half of a rapidly spoken language you barely understand is exhausting:

I went to my first entirely Hungarian math lecture today, AR’s big combinatorics seminar, which normally conflicts with the Putnam seminar I teach, which was canceled today since it’s an American holiday. They offered to lecture in English, but this was more fun, and I understood the math for the first half and just enough of the Hungarian to learn a few new words from context.