Aksel Sandemose, A Fugitive Crosses His Tracks (1923, translated to English in 1936. I read it in Swedish, En flykting korsar sitt spår when I was 16).

It was in a long list of books where we had to pick some of them as required reads. I found it intermittently boring, but it introduces the Law of Jante that became a cultural/sociological descriptor/phenomenon and is often referred to locally in Scandinavia but also internationally. It made me see things about my culture that I had not noticed before as they were so ubiquitous for me, having grown up immersed in it.