Salvador Dalí wore a 41; but when he painted, to stimulate his creativeness, he wore smaller shoes, specifically size 38. The discomfort activated ingenuity. 
In his Weimar home, Goethe wrote while sitting on a wooden trestle, like the “pommel horses” used by athletes in the Olympics. Rilke wrote standing up, at a high desk, also recited standing up and only sat to read. And in the Achilleion – the palace that Sisi built in Corfu – the office that Kaiser Wilhelm II used is preserved, with a kind of saddle where he sat to write.