Culture isn't logical. It's often totally arbitrary, and like religion, only looks sane from the middle of a crowd of people who agree to support each others' manias. When you first visit a culture different from your own, it's like coming across some island tribe who believes that humans were first carved from taro root and given life by the rainy season thunder, when everyone KNOWS Jehovah created the earth in 6 days. That is, the blatant artificiality of it all contrasts absurdly and maddeningly with the seriousness with which people take it.