bein- I do it sometimes, like just mumble to myself. Like if someone at home does something that I don’t like, I’ll mumble under my breathe. When speaking with my therapist recently, it happened to come up in convo. I told her that I thought it was so normal and that everyone does it but she said it is not. She said it can show something like a person doesn’t feel like they can talk to their family members (if it is a situation at home where u r talking to yourself). Or that in the family environment, it is not common for the family to discuss numerous things that come up.
I actually thought this was very interesting. I am totally not saying this is your problem at all, just saying that this is a discussion I had recently.