Is it normal that i act like someone is there?

Ever since i can remember iv been talking out loud, like i have someone there or some kind of audience. I have no friends or siblings and i am alone mostly. I would watch a video or play a video game, and when something happens i would comment on it out loud. Sometimes jokes or i would say "this is so weird" or "dude this is so cool", it can really be anything, even pull my hair or hide my laughter like someone is watching me. I know very well no one is watching me and i am completely alone, but when i remember then i start feeling bad. I would think of things like: "no one knows who i am", "if i died here no one would ever know who i was", "all these momments im experiencing, (fun/sadness) no one knows about them. It fills my hearth with sadness and i ask myself is it even worth living like a forever unknown person. Plase dont give me depression advice i just want to know why am i doing this or whats it called. The moments where i stop and think "why am i talking when no one is there" are rare, sometimes i would explain what i am doing or justify my actions. Everything out loud and knowing no one is there. Altho never in public or around other people, in fact i am very silent and shy.