I found out via my several years of helping clients quit smoking that when the smoker started framing the time after they quit as healing rather than "withdrawal" they had much fewer so called withdrawal symptoms.
Expectation produce powerful physical responses and when you really expect something it feels right that you are going to get it. People who expect to get drunk will feel and behave drunk when given fake alcohol; proven by research.
So if we can remove a large amount of expectation that nicotine withdrawal is going to be terrible then all a person has to deal with is the physical element of letting their body heal. This is why we use hypnosis - because it is much better at helping you change your expectations than will power is.
If someone is led to believe that withdrawal from smoking has to be awful then that belief and expectation may produce a large part of what they experience.
From our Smoking Cessation Program