“Well," he said, "I say, now, as I said then, that a man should keep his little brain-attic stocked with all the furniture that he is likely to use, and the rest he can put away in the lumber-room of this library, where he can get it if he wants it.”

“A man should keep his little brain attic stocked with all the furniture that he is likely to use, and the rest he can put away in the lumber room of his library, where he can get it if he wants it.”

“I consider that a man's brain originally is like a little empty attic, and you have to stock it with such furniture as you choose. A fool takes in all the lumber of every sort that he comes across, so that the knowledge which might be useful to him gets crowded out, or at best is jumbled up with a lot of other things, so that he has a difficulty in laying his hands upon it. Now the skillful workman is very careful indeed as to what he takes into his brain-attic. He will have nothing but the tools which may help him in doing his work, but of these he has a large assortment, and all in the most perfect order. It is a mistake to think that that little room has elastic walls and can distend to any extent. Depend upon it there comes a time when for every addition of knowledge you forget something that you knew before. It is of the highest importance, therefore, not to have useless facts elbowing out the useful ones.”

“That any civilized human being in this nineteenth century should not be aware that the earth traveled round the sun appeared to me to be such an extraordinary fact that I could hardly realize it.‘You appear to be astonished,’ he said, smiling at my expression of surprise. ‘Now that I do know it I shall do my best to forget it.’‘To forget it!’‘You see,’ he explained, ‘I consider that a man’s brain is like a little empty attic, and you have to stock it with such furniture as you choose. A fool takes in all the lumber of every sort that he comes across, so that the knowledge which might be useful to him gets crowded out, or at best is jumbled up with a lot of other things, so that he has difficulty in laying his hands upon it. Now the skilful workman is very careful indeed as to what he takes into his brain-attic. He will have nothing but the tools which may help him in doing his work, but of these he has a large assortment, and all in most perfect order. It is a mistake to think that that that little room has elastic walls and can distend to any extent. Depend upon it there comes a time when for every addition of knowledge you forget something that you knew before. It is of the highest importance, therefore, not to have useless facts elbowing out the useful ones.’‘But the Solar System!’ I protested.‘What the deuce is it to me?’ he interrupted impatiently: ‘you say that we go round the sun. If we went round the moon it would not make a pennyworth of difference to me or to my work.”

“It is a question of cubic capacity," said he; "a man with so large a brain must have something in it.”

“I say, Watson,’ he whispered, ‘would you be afraid to sleep in the same room as a lunatic, a man with softening of the brain, an idiot whose mind has lost its grip?’‘Not in the least,’ I answered in astonishment.‘Ah, that’s lucky,’ he said, and not another word would he utter that night.”

“Now, Watson,' said Holmes, (...) 'you'll come with me, won't you?''If I can be of use.''Oh, a trusty comrade is always of use. And a chronicler still more so. My room at The Cedars is a double-bedded one.'(...)'You have a grand gift of silence, Watson,' said he. 'It makes you quite invaluable as a companion. Pon my word, it is a great thing for me to have someone to talk to, for my own thoughts are not over-pleasant.”