When the callouses start to peel, he's in a hotel in Brussels. Well, not quite hotel. Hotels are clean, relatively safe things for the French on their August escape, the politician's respite from a tense day of negotiations at the EU or NATO... even the student backpackers' no-frills bunk as they make their obligatory trek across Europe- a questionable bathroom down the hall with the shower that you really should wear flip-flops while using- could be called a hotel. Not this. This is a mere building. No more than a structure. And parts of it seem as if they are barely standing. The atmosphere doesn't matter. He's here to listen.
His mind is occupied with learning Dutch, but that doesn't mean he doesn't notice. He grudgingly resents Mycroft's natural talent for languages and diplomacy, and replaces the envy with cynicism. He thinks of how some people were simply created to serve. A natural-born bureaucrat. No matter how high-ranking, that's all he is. A servant. He tries to take some comfort in the fact that he's not chained to a desk, despising legwork, and he will never be told there's no "i" in "team", or asked to help someone find a balloon with their name on it amongst the hundreds shoved into a glass-walled room in a conference center. (Now that's a proper hotel. It has things like a heater.) No matter how indispensable he is to New Scotland Yard, he is no teammate. But, back to the callouses. They are a small thing, but of course he notices. Even though he is far more likely to notice his surroundings than his own body.