Your adult human body is made up of around 40 trillion cells.
The interesting thing about this is that every cell is actually an intelligent unit with a cell membrane that has lots of receptors to respond to their environment. So your inner environment is important and includes everything we eat and every chemical in our body because they go to all your cells.
Your emotions and your habits cause chemicals, called peptides, to be released from your brain so it you are angry, every part of you is angry and your cells get addicted to anger if it happens often. The same applies to all your emotions, love, fear, joy etc. You become addicted to the emotion.
This is how addiction works and why an addiction is very hard to control with your conscious, logical mind.
Hypnosis also causes your mind to release chemicals and these remove the receptors for the habit or emotion that you want to get rid of. This makes changing that habit or the habitual emotion very easy.