On my way out of Tate Modern around noon today, I bumped into Nick Serota in the crowded Turbine Hall. “Hey,” I grabbed him by the sleeve, “what are you doing here?” He grinned at me: “How long are you here for?” “Oh,” I replied, “I just came to see the place on a normal day.” “It will be even more crowded in the afternoon,” he nodded knowingly. I followed him with my eyes as he mingled with the visitors. In the management literature, this is known as managing by walking around.