Human nature cannot be predicted. We all think that we know somebody. That means that we believe that we know how a friend or family member would react to a situation. We think that we know this at least about people we are very close to. Do we really? If that were true, relationship would not sour. Because our partner is surely a person we know a lot about. But suddenly we are confronted with a partner about whom our feelings change or vice versa. Why does this happen? I am not sure whether people change at all. But surely the way they behave or act is so unexpected that we feel they have changed.