And so, beginning in the early 1980s, I learned a new language. I began by purchasing Teach Yourself Czech. Taking advantage of the length (and increasingly welcome) absence of Wife #2, I devoted two hours a night to this book. Its method was old-fashioned and thus reassuringly familiar: page upon page of grammar, with the emphasis on the complicated conjugations and declensions of the Slavonic family of languages, interspersed with vocabulary, translations, pronunciation, important exceptions, etc. In short, just the way I had been taught German.
Learning Czech... made me a very different sort of scholar, historian, and person. Would it have made a significant difference had I taken up, say, Polish? My friends certainly thought so: to them, Czech was a small Slav language (much as Russian colleagues would later describe Polish) and I had inexplicably opted to specialize in what -- for them -- was the equivalent of the history of, say, Wales. I felt otherwise: that distinctly Polish (or Russian) sense of cultural grandeur was precisely what I wanted to circumnavigate, preferring the distinctively Czech qualities of doubt, cultural insecurity, and skeptical self-mockery. These were already familiar to me from Jewish sources: Kafka, above all -- but Kafka is also the Czech writer par excellence.
Tony Judt in the 10 March issue of the NYRB (behind paywall, bought by me in a bookstore that would appear to be about 2 issues behind the times). He decided to learn Czech, since you ask, because he was going through a mid-life crisis.