Some events are so emotionally charged that we form unusually detailed memories of when and where we heard about them. Examples include Paul Henderson’s winning goal in the 1972 hockey series Team Canada played against the Soviet Union, and the terrorist attack in the United States on September 11, 2001. These flashbulb memories generally persist much longer than memories for ordinary events.

CP IMAGES/PETER BREGG and KATHY WILLENS/AP PHOTO