There has been much written on mind-body duality. Some postulate that it can never be the case that the mind and body are separate, whereas others swear that they feel that they body is separate from the mind.
To me, it matter not what people think is the absolute truth, and only what you feel as an individual. Personally, I feel that my body and my mind co-exist, but are otherwise unrelated. One certainly affects the other, but the synergy is more one of flat mates than intimacy.
My body and my mind have very different personalities, which might account for the separation that I feel. My mind is very open and permissive, curious and courageous. My body is very modest and relatively reserved, content with not being curious and somewhat shy. For as long as I can remember my mind has dragged my body along on its adventures. Fortunately, my body is very easy going and perhaps even enjoys the extrovertedness that it doesn’t have to contribute to directly.
To the extreme, some people have a mind body duality that results in them dis-identifying with their body. They might look in the mirror and feel that body is not me. It could be that the difference between the mind and body personalities is so extreme that the two are difficult to resolve in any functional way. It makes me think that there must be people that have the reverse to be true, which is to say that they feel their mind is not their own and instead they identify with their body. I have found a word on the Internet for the latter: depersonalisation – a feeling that your thoughts are not your own. Curiously, there is no adequate word that I can find for feeling that your body is not your own. The closest I have found is dismorphia, but I elect the new word: decorporealisation – a feeling that your body is not your own.
There must be a threshold at which you notice the separation of the mind and the body. The attached graph shows what I mean, and locates my experience with an X marks the spot.