I assume I usually use "I", but when I dissapoint myself I'll say "you idiot". And sometimes I pretend different personas are watching my life through my eyes and I imagine what they surmise, but I'm still me and seperate from the personas.
And then there's Dave. When Dave takes over, look out. I'll black out for hours then wake up finding that Dave has got me into another fine mess, like getting into a fight with a stranger or setting a building on fire. But I expect that's something to which we all can relate.