" Thinkers aren't limited by what they know, because they can always increase what they know. Rather they're limited by what puzzles them, because there's no way to become curious about something that doesn't puzzle you. If a thing falls outside the range of people's curiosity, then they simply cannot make inquiries about it. It constitutes a blind spot — a spot of blindness that you can't even know is there until someone draws your attention to it. "