From reading too much, and sleeping too little, his brain dried up on him and he lost his judgment.
Miguel de CervantesDon Quixote followed nature, and being satisfied with his first sleep, did not solicit more. As for Sancho, he never wanted a second, for the first lasted him from night to morning, indicating a sound body and a mind free from care; but his master, being unable to sleep himself awakened him, saying, "I am amazed, Sancho, at the torpor of thy soul; it seems as if thou wert made of marble or brass, insensible of emotion or sentiment!
Miguel de Cervantes