There are a few conjectures. However, they are just that –conjectures. One of the most common is that Alfred Nobel decided against a prize in maths because a woman he loved married a mathematician. Another is that he did not care much for the subject as it was not a ‘practical science’ that could directly benefit humanity-which is the chief purpose of the Nobel Foundation. Others believe that since there already existed a well-known Scandinavian prize for mathematicians, Nobel may have seen no point in adding it to his list.