I include the seemingly odd choice of Tacitus’s Germania because it was a revelation to me when my father, a linguist, gave it to me for a translating exercise in my Latin classes with him. I was pretty fluent in Latin at that point and had read and translated many of Horace's odes, which interested me not at all.

My father, who loved Horace's odes, thought I did not like them because they were the reflections of an old man. And Germania, which describes the beliefs and culture of its people (whom the Romans conquered), also seems unlikely to interest a 13-year-old. But it was not Germania’s subject that engaged me; it was its incredibly taut prose, which I had never encountered before—cutting as a knife, attaining a precision I had not imagined possible. Here’s an example: “Quotiens bella non ineunt, multum venatibus.” (When they are not entering war, they spend much of their time hunting.) Six words in Latin, but fourteen in English—and English is a concise language!