It's totally normal. People like to overthink it and say it's muh autism and muh roleplay is autism, you are just muh schizo but it's just crap. There is nothing wrong in having fun with yourself. Imagine if you hated yourself though, what would be worse?
I keep talking to myself all the time, sometimes out loud but most of the time just in my head. I can process thoughts better, I can solve problems faster. I can get distance from myself in thoughts so it's like someone else is speaking with me; but I know it's me. So I tell on myself funny slurs and I laugh myself off because this is better way to cope with problems than pity. If I fuck up something I tell myself how niggerlicious it was or something like that, have a bit inner argument and move on. Maybe I don't have enough human contact at this point of life, I don't know.
My friend is like this too but the difference is she keeps talking to herself loudly while being in public places, like sitting in bus or whatever. Normalniggers don't understand this, we have sufficient inner life and we are intelligent enough to talk to ourselves without losing attention to context.