I just had a session on anxiety today, and the therapist mentioned how anxiety is there for a reason, and can have positive effects. He used the story of a pond of minnows. Half the minnows are confident, and the other half are anxious. On normal days, the confident minnows are swimming around, eating all the food and having a good life. On days when there is danger, the confident ones get eaten up fast, and all the anxious minnows who were already scanning for danger, survive. There is reason why anxiety continues to get passed down from generation to generation. Its not always a bad thing.