There are different parts of you as a whole. They can be classified under different schema. There is the mind that is your thoughts; the uncontrollable ones and the controllable ones together. These are largely effected by another part, the body, which can be thought of as the housing for all the chemicals and emotions. And then there is You; the you that exists before your thoughts. It’s the thing that observes your thoughts. It’s the thing that tries to reason and decide what you do and what you think about. Though sometimes it will lose the decision battle to your body and what it wants or the decision battle with the mind and the mind will run on uncontrollably.
In any case, it’s very useful to think about the separation of these parts. It allows you think about your emotions in a very interesting frame: “I’m really anxious today” transforms to “My body is very anxious today and my mind is out of control even though I know that I have nothing logically that should really make me feel that way.” It externalizes all these negatives.
Though we can’t control the body and the mind, we do have control over the observer. The observer is the little boy on the back of the very large elephant. He will keep on tapping the plodding elephant in particular directions. And over time, the elephant will learn. But it’s an elephant, it takes a long time will ignore you for a while. Your mind and body are the same. The observer needs to work consistently to actually make a change in the way the mind naturally thinks and the body feels.