This morning, I hung an American flag out the window of our London flat. It's an annual vigil I've followed since the morning of September 11, 2001.

Where were you on 9/11?  For our generation, it is undoubtedly the one moment in time that will collectively bind us together for the rest of our lives.

Eighty-one percent of all Americans say the 9/11 attacks were the most significant historical event in their lifetimes, according to a new Zogby poll. It's even higher for those of us who were physically closer to the attacks: 90% of East Coast residents agree with that statement, compared to 75% on the West Coast of the United States of America.

For our parents, it was the death of President Kennedy. For their parents, it was Pearl Harbor.  And for the rest of our lives, we will continue to quiz new friends and colleagues about their whereabouts on that morning in September.

Sometimes the stories are funny, like the person who did not find out about the attacks until several days later because they were on a camping trip. Or the friend who was called at 5am in Calfornia and told not to report to work, went back to sleep and was oblivious to the reason for the office closure until they woke up later that afternoon. Sometimes they are sad. Sometimes there is a personal connection. Sometimes they are lies, like the U.S. soldier I once interviewed in Afghanistan who told me of his "best friend" who died in the World Trade Center (the "friend" was not on the list of casualties). There is no right or wrong answer.  But they are all fascinating stories that provide a glimpse into our collective memory.

I (Mr. Crab) was at the Pentagon parking lot when the plane hit the south side of the building. The fireball and mushroom cloud over the Pentagon, the smell of burning jet fuel, the screams and prayers of a woman carried by her colleagues, the Army officer stumbling out with dust and blood covering his crisp uniform -- these images are still burned in my mind.

Six years on, the memory of 9/11 still seems like yesterday to me. And that's one memory I wish i could forget.