Bush is afflicted with a sort of tunnel-vision that makes his world-view quite narrow. A person afflicted with tunnel-vision isn't lying if he simply doesn't see things that are outside his narrow visual range. However, other people who know about his affliction have a responsibility to point things out to him when he misses them. In Bush's case, there seems to be nobody performing that function. On the contrary, his advisors seem to suffer from the same disease.