I Know What I Am Doing, but I Can't Stop Myself From Doing It

In the Gita, Arjuna asks Krishna why it is so difficult to change ourselves. He says: 'Why can't you stop yourself? Because there is this power within me, which impels me along this path' The moment he says that, Gita really begins with the tenth and eleventh verses of this second chapter. That's when Krishna starts teaching Vedanta.