It must have been around 1966 when I first met Klaus Krickeberg  at a conference in Greece. In my memory it was Konrad Jacobs  who encouraged some young people from Erlangen to attend. I  still remember when Klaus took us, M.~Sieveking, J.~K\"ohn and  me, to a quite exciting tour by car on the Peloppenese. Later on,  times were exciting too when I was around 1970 assistent to Klaus in Heidelberg. I also remember David G.~Kendall at the Greece- conference, telling us about the Delphi method. About this I had  forgotten until recently when writing this paper I noticed that my  current work on opinion dynamics is related to the Delphi method.