The adjective “quixotic” comes from the ambitious, yet head-in-the-clouds character Don Quixote, from the seminal, early 17th-century Spanish novel by Miguel de Cervantes. The book is now considered a cornerstone of modern literature, but it caused a fair bit of confusion when it was first published. Readers couldn’t agree on whether it was a straightforward comedic novel, a commentary on societal pressures, or a tragedy about the dangers of idealism. Today, the title character’s name is still used to describe someone idealistic and impractical, and the idiom “tilting at windmills,” which describes expending energy on an unrealistic goal, also comes from Cervantes’ novel.