What is the bigger challenge—for a student or the instructor to understand what is important in medical microbiology? Many years ago when I took my irst graduate course in medical microbiology, I read thousands of pages of text, listened to 5 hours of lectures a week, and performed lab exercises 6 hours a week for 1 year. I was given a wonderful foundation in microbiology, but I frequently asked the question—that was voiced by all the students—do I really need to know all this stuf? he answer to that question is certainly no, but the challenge is what information is needed. Years later when I set out to write my irst textbook on microbiology, my goal was to only give the students what they need to know, described in a way that is informative, factual, and concise. I think I was successful in that efort, but I also realize that the discipline of microbiology continues to change as do approaches to presenting information to the students. I am still irmly convinced that my eforts in my irst textbook, Medical Microbiology, and subsequent editions are important, forming the foundation of microbiology knowledge for a student. his cannot be replaced by a quick search of the internet or a published review because much of the subject matter presented in Medical Microbiology— epidemiology, virulence, clinical diseases, diagnostics, treatment—is a distillation of the review of numerous research articles and clinical and technical experience. Having stated that, students frequently turn to review books consisting of abbreviated summaries, illustrations (should I say cartoons), and various mnemonic aids for mastering this subject. As I have watched this evolution of learning microbiology, I am struck by the sacriice that has been made. I believe microbiology is a beautiful subject, with the balance between health and disease deined by the biology of individual organisms and microbial communities. Without an understanding of the biology, lists of facts are soon forgotten.