I was teaching Lazarillo de Tormes. My students hadn't read it (nor I, in the past 20 years), so I was improvising a lecture. I explained that it was a book about people too poor to have servants, who still had servants, and that the theme of the book was extreme poverty. Specifically, how not to starve to death (morir de hambre). I'm sure my lecture was wildly inaccurate in its details. After all, it was improvised with no preparation, and I gave it literally while sleeping.