The Sanskrit word Sakshi meaning witness or seer or your conscious self is used to refer to our inner being that is changeless, the passive witness of the changing states of mind. It is the ever-present knower/ experiencer in every experience, which can never itself be experienced.
It is that which illumines our conscious world like the sun and which itself never can be illumined. It is the subject of every object but which in itself cannot be objectified.
If you start crossing out everything that you are not, it is that which remains at the end of the exercise.
It is our very nature to be this Sakshi, this witness who is mindful of everything and which simply is.
Getting in touch with your inner witness is true meditation.