I appreciate how different I am from my younger brother, Dale Kim. For example, we have very different kinds of memory. I remember facts and ideas from many different sources. One time, I was relaying to him the history of Neapolitan pizza that I read in a magazine years ago, and asked if I was boring him. He said that talking with me is like talking to a Google search engine that runs automatically without any search queries. I took that as a compliment.
My brother, on the other hand, remembers events and people. He remembers the past in much greater detail than I do. He would ask me if I remember this friend or that incident, and I would always come up blank. He is able to remind me of childhood memories that are now lost to me.
We are able to learn from each other. I am his teacher; he is my historian. I am his encyclopedia; he is my archives. I help him understand the present; he helps me remember my past.
If we had a third sibling, I would bet that he or she would be a visionary, able to imagine and design the future.