There can be only one

Thursday's Times of London has an interview with Dubya. The scene-setting:

Mr Bush added a bust of President Eisenhower [in the Oval Office]. It sits to the left of his desk, made from the timbers of HMS Resolute, a Victorian transport ship, another gift from the British. "You’re probably the only people in here for whom I don’t need to explain what ‘HMS’ means," he says. "My Texas friends have no idea what I’m talking about when I tell them."

Does the confusion spring from there being other majesties besides him?