"It seems to me," said Sancho, "that the knights who did all these things were driven to them... but... why should you go mad? What lady has rejected you?
"That is exactly it," replied Don Quixote, "that's just how beautifully I've worked it all out - because for a knight errant to go mad for good reason, how much is that worth? My idea is to become a lunatic for no reason at all."
Miguel de Cervantes, from Don Quixote