An opening address should ask the right questions, which we expect to answer during the coming years. A good opening address should formu late hypotheses for falsification during the conference or in the near fu ture. Mter Dr. Groen's excellent lecture yesterday, I feel better about my task, because I feel I am not alone in asking the ten questions in my ab stract. It is an honor for me to give this short paper largely based on my expe riences during 15 years as medical director of a rehabilitation center in Ba varia, as a teacher at two medical schools in Munich and Innsbruck, and as an...