I was stationed in West Berlin from 84-88 and crossed into East Berlin at Checkpoint Charlie many times. The rapidity in which the Berlin Wall, and the rest of the Communist empire, collapsed was nothing short of stunning.
I was there after you left. 1990. We took the UBahn to Alexander Platz when it finally opened. This was the subway station the trains went past because it was in the East. Armed guards could be seen when the train rushed thru....
Anyway, we (I was TDY at Templehoff—staying upstairs right by the bowling alley) got off on this newly opened station and went upstairs/outside to see the glory that was communism... And the first and only store there was named “International Sex Shop”.