My father was a practicing psychotherapist. He of course kept information he learned in therapy confidential, but he would occasionally report that a client would turn to him and say: "Doctor, I have a problem. I talk to myself". He would, in situations such as these, try to explain to the client that we all talk to ourselves, or at least that we should. We think things out, trying to make sense of the world around us and what happens to us, and that we often do this in words. Vygotsky is reported to have once said:
A thought may be compared to a cloud shedding a shower of words.