When I was a freshman in college, I did the classic move of taking an Intro to Psychology class that had about 700 people in it in a gigantic auditorium where it was impossible for me to pay attention. One thing I did remember was the concept of flashbulb memories.
People can remember minuscule aspects of days long gone by if they’re associated with a huge event. For a specific generation, they could all tell you where they were the day John F. Kennedy died, but probably not what their day was like on November 21, 1963. The professor asked if anyone knew what they were doing on September 10, 2001.