...he spent whole days and nights over his books; and thus with little sleeping and much reading his brains dried up to such a degree that he lost th… - Miguel de Cervantes

Finally, from so little sleeping and so much reading, his brain dried up and he went completely out of his mind.

with little sleep and much reading his brains got so dry that he lost his wits.

And thus, from too little sleep and too much reading, his brain dried up and he completely lost his judgment.

Not with whom you are born, but with whom you are bred.

I shall be as secret as the grave.

As regards your government of yourself and your household, Sancho, my first piece of advice is to be clean and to cut your fingernails, and not to let them grow long, as some people do, moved by ignorance to believe that long nails make their hand look beautiful, as if those appendages, those excrescences that they leave uncut have any right to be called fingernails at all, because they are more like talons of a kestrel: a monstrous and filthy abuse.