“Whatever is there in the mind, you are the witness of that mind. And the witness is ever separate from the mind. The very fact that you’re the knower of the mind means that you are not the mind.”
This quote by Swami gets to the heart of the matter from the perspective of Vedanta. Are you your mind or are you the witness of the mind? Of course, the mind will insist, “Of course I’m my mind, what else?” But if you are the mind, what knows of the mind? For example, if I know of this cup of coffee next to me, then I know that I am not that cup of coffee. I am what is aware of it.
This is not something to be taken on belief, but must be confirmed in one’s own experience, repeatedly, until it becomes obvious and clear.