The Thing
Since you had no input to your constitution, you could be considered a thing.
It should be no surprise that you are the result of a purely biological process. Your parents had a good time (we assume) one day, and about nine months later you appeared as a separate entity. You didn't ask for this and had no input on your constitution. In other words, you are a thing produced by nature. The process of shaping you as a thing continues as the environment shapes you, along with the input from parents and other major influencers. You didn't ask for any of this either; it simply adds to your "thingness".
So, here you are, a thing that believes it's a person. The illusion of selfhood is a brilliant strategy on nature's part, ensuring you will strive all the harder to serve this thing's primary drives: survival and procreation. You didn't choose these drives; they are integral to your thingness.