I never talk to myself..
Yesterday when I was at my friend's home, I went to the bathroom.. While I was out there I heard my friend talking to herself. As I returned she stopped talking...
And then I started to wonder: "Do everyone talk to themselves when theres nobody around?"
...
I simply NEVER talk to myself when I'm alone in a room! But as soon as someone step in, I just start having a conversation with myself.
I stop talking as the person leaves, and stays quiet until someone again steps in the room.
(When I'm home, and it's my family walking around)