Have you ever written about yourself in the third person? I think about myself that way sometimes, narrating to myself in my head. I don’t know why. No doubt is has some deeply psychological meaning about how I see myself and myself in the world around me. Blah, blah, blah.
Write about yourself in the third person. Narrate something as you are doing it, you don’t have to say it out loud (unless you have the place to yourself, then you really should say it out loud just for the experience). How do you describe yourself? Keeping in mind you can’t think of yourself the way you usually do, the narrator is more objective than you are. The narrator isn’t actually you after all, just an outside sort of anonymous voice over.