Having twin boys gives you a front row seat on the differences between nurture and nature.
My two boys are a minute apart in age. They live in the same environment. They both play hockey. They have two younger sisters and shared friends. They have tremendous similarities in many ways, but they are decidedly different in others.
My oldest boy is excellent at spelling but struggles to understand math problems. His brother, a minute younger, can do complicated math in his head yet has trouble spelling "complicated".
Each of them is unique. The different combinations of nature and nurture in each of them makes them different from each other and each interesting in their own way.