By Johannes Eisele, Reuters People walk next to giant domino pieces, placed along a stretch of the Berlin Wall’s original path, near the Brandenburg Gate in Berlin on Monday. Germany is marking the 20th anniversary of the fall of the Berlin WITNESSES OF THE WALL Many readers said they remembered the Berlin Wall and its collapse. Here is a sampling of their memories: I lived in Germany as a military dependent, and later as a U.S. serviceman. What a great country. I was able to take my children behind the wall when it still existed … –lepatriot I happened to be there on business when it came down. Three young…