Senta was around my age, had red hair and described herself as a Brooklyn babe. She was our guide on the open-topped bus tour of that part of New York, and the cadences and animation in her voice were such that she would have been worth listening to had she merely been reading out the Brooklyn electoral roll.

Scott collected money for the homeless on Broadway between 75th and 76th Street. He caught our attention when he called out “Ain’t she adorable!” to my daughter. We had just eaten a stereotypically large breakfast of waffles (cue passable Donkey from Shrek impersonations by offspring) and stopped to blether with him for a time.

Then there was the old fellow who looked like everyone’s idea of “Coach” from an American TV programme about a failing but on-the-turn baseball team. He became our self-appointed mentor on the Staten Island ferry and, like Senta and Scott, was an excellent ambassador for the people of the city.

They made Ground Zero all the more poignant. I defy anyone who has spent any time in New York, whatever their views on US foreign policy, to go to the site of the World Trade Center and come away thinking that New York and New Yorkers deserved this.

At street level, there is a blue cubic structure the size of a large garden shed. It bears information on the plans for the site and has quotes from those who were caught up in the attack. It was impossible not to be moved by these words or by the list of more than 3,000 names recording those who died. Down below, you can look through wire mesh at the work that is going on in the site. Someone had left a bunch of flowers, now withered, tied to the screens.

As we waited for the lift to take us back to the surface, a voluble, round man, pushing a cart of ice, berated inventively those who were using the elevator and who, in his eyes, should not have been doing so. Like a rude bit in a Shakespearean tragedy, he gave us respite. He could not, however, take away the feeling that I had. There are ghosts, and they have existed for as long as we have had language and symbols like the flowers on the fence.