Our psychological lives have a personal character. The subject is the subject of experience, but also of agency and ownership. Why is this, and what does it mean for the existence and nature of the self? Being Someone attempts to answer this question. I offer an original analysis of the personal subject, supported in part by the observations and insights of philosophers such as William James and Mary Calkins. I then engage with Nyāya arguments in favour of and Buddhist arguments against the existence of substance selves, as part of my own case for the former view. My argument is that personalness is unique and irreducible, so that nothing but the existence of a self that is concrete, property-bearing, enduring, and unified can adequately explain its existence and nature.