I assumed since it was invisible to me , it was invisible to everyone . This is also probably a form of confirmation bias . Actually this might be related to another cognitive bias people exhibit - what I call the I ' m Special bias . Basically , I think asking people why they do things is pointless - they do n't know and , worse , everyone in the world believes they are special .

Question: Why do most people believe they are unique ?
Answer: Because their mothers told them so .Because of the special bias .Because the world tells them so .Because of the confirmation bias .