Sir Peter Brian Medawar (1915–1987) is the greatest British biologist of the twentieth century, a Nobel Prize laureate, one of the founders of modern transplantology. A scientist, like Caesar in the famous Roman saying, is “only a man.” Scientists, like all other representatives of humanity, go to work every day and return home, experience ordinary human feelings and emotions. Peter Medawar addresses precisely the practical, everyday side of life of people engaged in research activities or just preparing to embark on this path. How to choose the right field of research for yourself? How to avoid excessive “scientific fanaticism”, which can negatively affect family life or relationships with a loved one? How, finally, not to succumb to despair when a theory that seemed unshakable suffers a crushing failure, and research again and again does not lead to the desired result? And these are just a few of the important questions that Medawar gives answers to in his wonderful, smart and full of good humor book.