It's often the anxiety that keeps one awake, although we've learned to live with it. There are moments when I'm busy doing something that needs concentration when I can sort of forget about the past and the future and concentrate on the very immediate present. After a while, the prickly feeling of anxiousness dulls and turns blunt. Have you ever left the house and worried that you didn't turn off the oven or the iron? That's what the feeling turns into- except it lasts all day… and night… and week… and month, after month, after month until you don't notice it except at night.