I was on the 10th floor of 2 World Financial Center (the building on the left, below). We thought the first plane was maybe just a misguided plane out of Teterboro. I called home and told my wife that she would probably hear about this but I was fine. I went back to the corner office on that floor to look at the WTC and then the second plane hit in a huge, huge ball of fire. I remember immediately thinking that I had just seen many, many people die. My second thought was to realize it was not just some horrific accident and we started clearing people out of there.
I started walking north with a huge crowd of people and eventually, late in the afternoon, was able to get a train out of Grand Central. I'll never forget the north tower having a plane shaped hole in it before it collapsed. I was about a mile away by that point. After some months, we went back to work down there and I worked about 4 more years before deciding I had had enough and was luckily able to retire when I was 52. People yammer about "never forget" and i don't see how that is remotely possible.
[Tony T: I was not referring to your particular reference re: "never forget". More about what I see on bumper stickers around the NY area.]