As a reference point of time, we 60-somethings will never forget where we were on the day JF Kennedy was killed. (check out this article called JFK Moment Frozen in Our Memories) http://www.deseretnews.com/article/525039299/JFK-moment-frozen-in-our-memories.html
The world has changed since then, and still changes, day by day. The way it was, before September 11 will fade in your memories, like those who died or moved away early in your life. Those of us who are 60-somethings--who rode our fat tired bikes freely in our neighborhoods in the fifties, came of age in the sixties and traveled the world with our backpacks in the seventies will remember a simpler world, with more people to people access and less time in front of a screen.