I agree w/ the others, you aren't causing any harm. If it's soemthing that bothers you than you could work on consciously catching yourself but I really don't see why you'd need to unless for you not others. I talk to myself when I'ma lone ALL THE TIME! If I'm not alone it's internal like crimgoddess said. For me I know I'm an analytical person and I think it's just part of it, I don't knwo if that is so for you too. But I think it'skinda cool.
\"As soon as you trust yourself,you will know how to live.\"
Johann Wolfgang von Goethe
\"Do not anticipate trouble, or worry about what may never happen. Keep in the sunlight.\"
Benjamin Franklin