That's interesting. Usually, I would ask if you have ever had difficulties focusing your attention, some ADHD? How do you grade your visualization? Can you cre

That's interesting. Usually, I would ask if you have ever had difficulties focusing your attention, some ADHD? How do you grade your visualization? Can you create a scene in your head and control it 100%? How often do you get a random song stuck in your head? I think that more people are prone to this than they think but they are simply not aware. Some people start realizing things when they end up trying some kinds of meditation practice and since they are not in control and somewhat clueless about what's happening internally, for some of them it sends them off the rails (hence the stories we hear about meditation triggering psychosis etc...) Some people never experience such things as well. For some, it comes later. Talking to oneself is fine. Feeling external thoughts, emotions and even minor loss of self agency in motor control is something else and I think that some rationalizations could make sense. But the current lack of understanding is leading people to handwave (not every scientist is so handwavy of course). There is an issue of depersonalization such as seems to be the case with your friend. All these things are really not understood and the nervous system alongside the brain is quite inscrutable for now.