How do I know who I am?

Lately I’ve been thinking and…Mostly everyone knows my personality as Vincent, but everyone knows me as Brennen. It’s like I have two people inside me. Or it’s like a dark side of me and light side of me. I know it doesn’t really make much sense…Just that how do I know who I really am? Nobody likes Brennen and everyone accepts Vincent. Any thoughts or ideas on it? I’m lost with myself…