...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.

His fantasy filled with everything he had read in his books, enchantments as well as combats, battles, challenges, wounds, courtings, loves, torments, and other impossible foolishness, and he became so convinced in his imagination of the truth of all the countless grandiloquent and false inventions he read that for him no history in the world was truer.

The very remembrance of my former misfortune proves a new one to me.

-->* I was so free with him as not to mince the matter.