In the early 1970s, as a young man new to London, I visited the Tate Gallery for the first time. The gallery wasn’t very full on a spring weekday morning, but one middle-aged couple came into the room where I was standing in front of a picture. Obviously, they were intent on doing the whole gallery at a brisk pace as they moved diagonally across the floor, glancing from side to side, like pigeons looking for food. Near the doorway, the woman halted to looked at a painting. She read the label out loud, ‘A Hilly Scene. Samuel Palmer,’ then stood back, and said, ‘My goodness, but it’s so small.’ And then they hurried off into the next room, perhaps to comfort themselves with some huge Victorian landscape.