Exam coincidence

I was taking the Oxford University entrance exam at school in Birmingham in 1981. One of the papers I had to take involved writing a precis of an unseen passage and then answering questions about it. On the morning of that paper I chose to practice by taking a book from the school library shelves (Rousseau's The Social Contract - not quite a random choice since I chose something that interested me but not something I had any reason at all to believe would figure in the exam), selecting a page at random and writing a precis of the argument. That afternoon the unseen passage in the exam came from the same section of the same chapter of the same book. When answering the comprehension section of the paper I was able to discuss in detail the way that Rousseau developed his argument in subsequent pages. I worried for weeks afterwards that the examiners would think that I must have cheated somehow because I showed specific knowledge that was so improbable.