Sherlock ‘Holmes claims he does not know that the Earth revolves around the Sun, as such information is irrelevant to his work. Directly after having heard that fact from Watson, he says he will immediately try to forget it. He says he believes that the mind has a finite capacity for information storage, and so learning useless things would merely reduce his ability to learn useful things. Dr. Watson subsequently assesses Holmes’s abilities thus:
Knowledge of Literature – nil.Knowledge of Philosophy – nil.Knowledge of Astronomy – nil.Knowledge of Politics – Feeble.Knowledge of Botany – Variable. Well up in belladonna, opium and poisons generally. Knows nothing of practical gardening.Knowledge of Geology – Practical, but limited. Tells at a glance different soils from each other. After walks, has shown me splashes upon his trousers, and told me by their colour and consistence in what part of London he had received them.Knowledge of Chemistry – Profound.Knowledge of Anatomy – Accurate, but unsystematic.Knowledge of Sensational Literature – Immense. He appears to know every detail of every horror perpetrated in the century.Plays the violin well.Is an expert singlestick player, boxer and swordsman.Has a good practical knowledge of British law.’
[http://en.wikipedia.org/wiki/Sherlock_Holmes]