Is it normal that i habitually act out conversations?

So I've noticed I do this often. Probably at least once a day, sometimes countless times in one day. I find my self unintentionally ACTING out conversations with people when I by myself. When I mean act I mean everything from factial expression to tone of voice. No not in my head, but acting out the situation as if its actually happening in person. Imagine an actor practicing his play by himself. And I do it unintentionally, not that I'm "practicing a speach for class" or "how I would break up my boyfriend" but just random things random "pretend" conversations with people who actually exist in my life..