Summarizing one’s achievements, especially for a distinguished scholar like Michael (Mike) R. Hoffmann, poses an absolute challenge. It is particularly poignant that due to his current health situation, he is unable to personally write a biography. After extensive discussions among the coauthors (D.B., W.C., and K.C.), we have decided to make our best efforts in collecting, editing, and reorganizing Mike’s previously written articles to create this “quasi-autobiography.” The biography encompasses various elements, including (i) a message from Mike (reproduced from the preface of abstract book for “3rd International Workshop on Frontiers in Environmental Chemical Research in honor of Prof. Michael Hoffmann’s 70th birthday” held in Pohang University of Science and Technology (POSTECH)), (ii) an academic career overview, (iii) his research trajectory, and (iv) his contributions to environmental sustainability. These sections aim to provide a partial portrayal of Mike’s academic journey, primarily as a professor first at University of Minnesota (1975–1980) and subsequently (and mostly) at the California Institute of Technology (Caltech, 1980–present). We sincerely invite the readers, including his academic descendants as well as the past, present, and hopefully “future” colleagues, to gain a deeper understanding of how his accomplishments have significantly influenced the fields of environmental and energy science and engineering in “practical” ways.