Certain events - often cataclysmic ones - stand out in bold relief in our memory. Those of you who are over 35 or so, think of where you were or what you were doing when you heard the news that President John Kennedy had been shot. You may not remember the date - it was November 22, 1963 - but you will probably remember other things about that day. Or if you are sixty or more think of what you were doing when you learned that Pearl Harbor had been attacked. Chances are some things about that day are etched clearly in your memory. People who were in the region of San Francisco on that fateful day in November, 1989, will always remember that the ground shook and freeways collapsed and buildings crumbled. Chances are that people on the eastern coast of the United States will never forget the …