Milsa
Everyone thinks 100% all of the time. Even when we sleep, another part of us processes things, hence the dreams ....it is usually called, the inner dialogue because sometimes nasty or shameful thoughts occur and the moral compass has to correct this thought
I think at that level it could become concerning. If the nasty and shameful thoughts appear real, then you are talking about psychosis (which is always a negative and usually persecutory, real-sounding voice of a third person, running continually in the head).
Whilst the person still has insight, it is important that they seek medical help. If someone has this but is not bothered about it and does not feel paranoid or persecuted, then it’s not psychosis.
Sorry to put a downer on this thread, but it is important to be aware as this is something that can come along at a later age, independent of any dementia or similar.