Photographic Memory

I once "brought the house down" in a class debate in seminary, when someone asked me: "Where do you get that?" I said: "It's on page seven, Roman numerals, in the Preface, top left." Both son M and I have what is called a "photographic memory". But it isn't really. It is said to be the degree to which one can remember things. With me, it works best where I was keenly interested in something -- intently focused on something. For instance, if I read something relevant to me, ten years ago, or even twenty or thirty, I will find it quickly in a pile of hundreds of books. OBSERVATION: I thought that everyone worked this way -- until I discovered that they didn't. But it is rather a useless ability if one sees a "photo" of something, say, like a classified document. One can't plug one's mind into a printer to produce the photo!