As the art historian Jennifer Roberts argued several years ago, “Just because something is available instantly to vision does not mean that it is available instantly to consciousness.” Or, as she also puts it, just because you have looked at something doesn’t mean that you have seen it.
The inimitable G. K. Chesterton once said, "There is a law written in the darkest of the Books of Life, and it is this: If you look at a thing nine hundred and ninety-nine times, you are perfectly safe; if you look at it the thousandth time, you are in frightful danger of seeing it for the first time."