By the time we arrived at the museum, having dealt with heavy traffic, it was past four o’clock and my brain had begun to endure its familiar siege: panic and dislocation, and a sense that my thought processes were being engulfed by a toxic and unnameable tide that obliterated any enjoyable response to the living world. This is to say more specifically that instead of pleasure—certainly instead of the pleasure I should be having in this sumptuous showcase of bright genius—I was feeling in my mind a sensation close to, but indescribably different from, actual pain.