"Sólo ha pasado una cosa importante durante los últimos tres días, y es que nada ha pasado". - Arthur Conan Doyle

Now, Watson, confess yourself utterly taken aback,” said he. “I am.” “I ought to make you sign a paper to that effect.” “Why?” “Because in five minutes you will say that it is all so absurdly simple.

"How do you know that?"
"I followed you."
"I saw no one."
"That is what you may expect to see when I follow you."

Problems may be solved in the study which have baffled all those who have sought a solution by the aid of their senses. To carry the art, however, to its highest pitch, it is necessary that the reasoner should be able to use all the facts which have come to his knowledge; and this in itself implies, as you will readily see, a possession of all knowledge, which, even in these days of free education and encyclopaedias, is a somewhat rare accomplishment.