<p>A short while ago, I chanced to be in Dallas, Texas, making a documentary film. One of the shots involved a camera angle from a big commercial tower overlooking Dealey Plaza and the former "book depository," and it was later necessary for us to take the road through the celebrated underpass. The crew I worked with was younger than I am (you may as well make that much younger) and consisted of a Chinese-Australian, an English girl brought up in Africa, a Jewish guy from Brooklyn and other elements of a cross-section. As we passed the "Grassy Knoll," and looked up at the window, and saw the cross incised in the tarmac, I was interested by their lack of much interest. The event of Nov. 22, 1963 isn't half as real to them as the moment, say, when the planes commandeered by suicide-murderers flew into the New York skyline. Nor, as I realized, is it half as real or poignant to me as the site of Ford's Theater in Washington D.C. Time has a way of assigning value.</p>