There is universal agreement that the Nobel Prizes, given to individuals who have made an extraordinarily notable contribution to humankind in the fields of chemistry, physics, physiology or medicine, literature, and peace, are the most prestigious prizes offered for human achievement. This commentary gives an overview of the basis for Alfred Nobel writing his third will that established the five prizes and includes a discussion of why those five fields were chosen. The commentary includes factors that influenced his choices and contains examples of controversial selections or omissions, especially in the earlier years. A few were errors of omission (e.g. Tolstoy, Tesla, Edison, Best, Gandhi, Franklin), some errors of commission (e.g. Fibiger, Moniz); but, given the complexity of the task, the error rate is small. In some cases, the conclusion that an error had been made is debatable. Such decisions are difficult. Arne Tiselius, a Nobel laureate in chemistry and President of the Nobel Foundation said that one cannot in practice apply the principle that the Nobel Prize should be given to the person who is best; it is impossible to define who is best. Hence, there is only one alternative: to try to find a particularly worthy candidate. This paper includes a brief review of the integration of the Sveriges Riksbank Prize in Economic Sciences in Memory of Alfred Nobel, established in 1968, and added to the original five Nobel Prizes; the prize was first awarded in 1969. A short discussion on the absence of a Nobel Prize in mathematics is provided. Adaptations to the development of “big” science, especially in physics, may require the Nobel Foundation to extend its limit of no more than three awardees for the prize in physics and, perhaps, other scientific disciplines.