Once I heard an interesting story about our brains. Young born babies do not recognize their surrounding world as we mature persons do. They see things differently from us. For example, a triangle is not a triangle for them. It might be just a dot, a circle, even a strange animal or whatever. This is one of the two reasons for children's paintings are sometimes quite unique. The other reason is that their controls of their hands are too immature to draw lines as they want. Usually, they acquire the ability to recognize things correctly. However, I wonder what is correct -- no one can prove that a triangle is a triangle. There is even a possibility that every triangle which everyone of us recognizes is different each other. Anyway, you might say why I think such a strange thing. Because, when I was walking up this escalator half asleep this morning, I lost myself for a moment and I couldn't tell whether the escalator was going up or down. Human recognition is not so reliable, isn't it?