I have to say, one of my middle school teachers read us a book once about a mouse (or some type of animal) hibernating for the winter his log home near the field, woods, and stream. In the deep months of the winter cold, he found he would talk to himself, quite frequently in fact, as there was no one else to converse with.
He didn't find it a bad things really, as it passed the time and arguable kept sharp his mind, but felt as though he crossed a line somewhere when he began having arguments with himself and answering his own questions.