Another great book is The Courage to be yourself. Sue Patton Thoele. The sadness, I believe, is from being "dead" before you are - I finally decided it is not on me to carry the load for whatever the child is going through. In my late 60s, I feel like time is limited to share more experiences, but it is less painful to find my life and joy in other places. Also, it helps to keep in mind that your child may not be able to give you what you need.