Is it a mental illness to always fantasize about talking to others?

From a very young age, as long as one was not focused on one thing, that is, when one's mind was empty, such as walking on the road, taking a car, etc., one would pretend to talk to others. The target of the conversation was not necessarily someone they knew. The topic of conversation also depended on the situation at that time. For example, if one happened to encounter something, one would immediately "talk" to someone, just like chatting with ordinary friends. Sometimes, he would imagine a scene or plot, and then "perform" in it. I used to think that everyone was like this. Later, I asked my classmates and found out that they didn't. I didn't take it seriously because it didn't affect my life. I thought I was just too eager to talk, so when no one was talking to me, I would assume that my friends were listening to me. It might be related to being a single child. I didn't communicate with my parents at home, so I found another way to vent. But now, the situation was getting more and more serious. In the past, most of the time, it was just the activity in his head. In the past two years, his mouth often moved involuntarily. Sometimes, the onlookers would find it strange that this person was talking to himself and even making sounds. And it happened almost every minute (except when I was concentrating on work and talking to others). Sometimes, when I was with a group of people, I would fall into my own fantasies. I didn't know if this would develop into a mental illness, and I was getting more and more worried that I couldn't control myself from talking to myself in public.