Abstract My first years in science were spent as an inorganic chemist at Uppsala University studying adducts between Lewis acids and bases by X-ray crystallography. A postdoctoral year in Cambridge at LMB converted me from a rather ignorant chemist to a devoted molecular biologist and I have studied structure and function of proteins ever since. The first major project after returning to Uppsala focussed on alcohol dehydrogenase for which we could postulate a detailed mechanism of action based on structure determinations of a number of complexes in two different conformations. The second major project involved Rubisco, the enzyme that catalyses the initial carbon dioxide fixation in green plants. Towards the end of my scientific life I spent five years as research director of the European Synchrotron Research Facilities in Grenoble, France. I was responsible for building up experimental facilities for chemistry, biology and medicine and managed to promote strong facilities for structural biology. In my spare time between these activities I wrote a textbook on protein structures with John Tooze, for many years coeditor of the journal Structure with Wayne Hendrickson and later Alan Fersht and I have spent a large fraction of my time on matters of science policy and advice.