Mark Twain, A Connecticut Yankee in King Arthur's Court

"But it is a blessed provision of nature that at times like these, as soon as a man's mercury has got down to a certain point there comes a revulsion, and he rallies. Hope springs up, and cheerfulness along with it, and then he is in good shape to do something for himself, if anything can be done."

"You can't depend on your eyes when your imagination is out of focus."