The author reflects on his medical career, beginning with his graduation in 1973 and his professional registration signed by Miller Guerra. He pays tribute to Miller Guerra, a distinguished neurologist, academic, and politician, recalling a 1966 lecture where Guerra argued that modern, effective medicine is a relatively recent development, spanning only about 100 years. The author supports this view by highlighting the dramatic increase in life expectancy from the mid-19th century to the present, driven by key scientific breakthroughs such as anesthesia, antisepsis, the germ theory of disease, X-rays, aspirin, and radioactivity.