I cannot live without brainwork. What else is there to live for? Stand at the window here. Was there ever such a dreary, dismal, unprofitable world? See how the yellow fog swirls down the streets and drifts across the dun-colored houses…. What is the use of having powers, Doctor, when one has no field upon which to exert them?

The lines are spoken by Sherlock Holmes to Dr. Watson during a lull between cases, when Holmes is restless and dissatisfied without an intellectual problem to occupy him. He stands at the window in Baker Street, looking out over a fog-bound London and lamenting the dreariness of ordinary life. The moment underscores a recurring element in the Holmes stories: his dependence on “brainwork” and the way boredom drives his moods and habits. Doyle uses the scene to contrast Watson’s steadier temperament with Holmes’s need for challenge, and to frame the coming investigation as a welcome “field” for Holmes’s exceptional abilities.

Holmes equates living with thinking: without demanding mental work, existence feels empty and the world itself appears “dreary” and “unprofitable.” The foggy cityscape mirrors his internal stagnation—London becomes a visual metaphor for boredom and lack of purpose. The quote also reveals Holmes’s quasi-heroic self-conception: he has “powers” that require a proper arena, implying that talent without opportunity is a kind of torment. More broadly, Doyle is dramatizing a modern anxiety about specialization and meaning—when one’s identity is built around exceptional competence, ordinary life can seem intolerably thin unless it offers problems worthy of that competence.