Levi quotes my favorite bit from the letters Nabokov wrote to Véra (printed in a recent New Yorker) while he was on a college lecture tour in 1942.
At the station in Springfield I was met . . . by the club secretary, a creepily silent melancholic of somewhat clerical cast with a small stock of automatic questions, which he quickly exhausted. He is an elderly bachelor, and his profession consists of doing secretarial work for several Springfield clubs. He livened up and flashed his eyes one single time--got awfully nervous, having noticed that the flagpole by the Lincoln mausoleum had been replaced by a new, taller one. It turned out that his hobby--or, rather, the passion of his life--is flagpoles. He sighed with relief when a watchman gave him the exact information--seventy feet--because the pole in his own garden is still ten feet taller.