...found myself going for long walks

Sometimes I had very little to do in the evenings. My old friend Dr Watson was occupied by his new ménage, no troubled visitor had come to my door, or I had run out of cocaine, and so I found myself going for long walks.

That was fun. But it was disturbing to come home and hear the upstairs neighbours spring to life as soon as I set foot in the door. It happened all the time. I would ease the door shut behind me, pause, and the next thing was an excited scrabbling from overhead, as if they had been lying around in a daze until my return, not knowing what to do with themselves, and now they were galvanized into activity. “He's back! What now? Quick, the TV! Let's chase each other and climb on the furniture.” But at least their noise was sporadic. I used to live next to a man who was smashing atoms in his living room. That's very difficult, and the work can't stop for anything if it is to be successful.