My second trip to a divided Berlin was in August of 1983. I’d been to the city in 1975 on a brief visit with my father. The details of that visit were already a blur eight years later, but some enduring impressions accompanied me on my return trip. My second visit was to last for nearly three years, plenty of time to test those earlier impressions, form new ones, and store a myriad of details into my long-term memory.

Th...