Professor Max Delbrück was a charismatic scientist, and winner of the Nobel Prize in Physiology or Medicine in 1969, who gathered around him numerous students, colleagues and friends to explore modern quantitative approaches to biology. This small book is a collection of personal reminiscences given at a Centennial Celebration of his birth at the University of Salamanca, Spain, in October 2006 by those who primarily joined Max in a search for understanding sensory transduction. Included among the twenty-three chapters and three appendices are several chapters by persons unable to attend as well as some talks presented at other centenary celebrations for Max. In addition three of Max and Manny’s children shared memories of their family life and activities. The book was organized and edited by Walter Shropshire, Jr., at the invitation of the Salamanca organizing committee, to make these stories available to a wider audience, even though Max is well known and respected within both biology and physics research communities. It is hoped that these anecdotes and insights honoring the life and work of Max will be an inspiration to others as an example of how to enjoy the creative play of innovative and significant scientific research.