ALL the time. It is one of my favorite pastimes.
I've thought of getting a personal recorder so I would look like I was on the cell. I have memory problems and sometimes I come up with some pretty good ideas.
Not only do I talk with myself but I'm a very animated talker. This means bystanders get quite a show too. Gee maybe I should get paid for my performances.
My saving grace......the average in my area is 85. So I fit right in.