This question has an infinite number of responses. Every one of those responses so far address your question. A person replying with a joke is responding to your question, it isn't not formulated as a direct response but it is telling of who they are.
Want to know who I am? I don't identify myself by what I do or who I know or what I wear. I don't identify quickly with most people that are younger, older or my own age. I don't identify myself by spreading my thoughts and beliefs to others. This is about as specific as I can get. The remainder of what I am not is exactly who I am.