I don't know why I have this habit

Sometimes (most of the time) I announce whatever I am going to do before I do it.
My partner asks why I say stuff out loud, when there's nobody that I would need them to hear, like saying that I'll brush my teeth before replying to a text, or saying out loud that I'll stop walking to check something out before doing so.

I really don't know why I do it. I default to "it's just a thing I do, I guess".

One guess is that I might be trying to let people into what I'm doing. If I know they know, then they know that they can participate or stay out, depending on what it is that I am doing. If I see a cool bird I wanna stop to look at, they can do it with me and not have to guess what I might be doing. If I'm texting someone, they can know not to say anything to me so that I can type, shit like that.

Another guess is that I could be needing, on some level of consciousness, to declare things and actions or have them declared to me beforehand so they're more real, so things don't happen out of nowhere, and my actions exist in the world before anyone tries to push me in another direction.

I mainly do this when I'm doing things I don't normally do (as in, idk, listen to music while showering, or going on some voice-chat to play videogames). That gives me a clue: it has something to do with breaking a routine, but that's it. I don't know anything else.