Don't know about pure nicotine, but i guess it's easier to get away from it than from tobacco with its dozens or hundreds of secret additives.
Nicotine is more or less like caffeine. If you can't drink your usual cup of coffee or tea, you may get a headache and be a little grumpy. After a while these "withdrawal symptoms" will disappear. What makes cigarette withdrawal so difficult is definitely contained in the thousands of additives found in cigarettes today. One of them might be monoamine oxidase inhibitors, I do not know if they are naturally present in tobacco, but if someone responds to them and want to stop smoking, it could make it very difficult.
Both Nicotiana tabacum (common tobacco) and Nicotiana rustica (the more poisonous wild variety, often used by the heathens in their shamanic ceremonies) contain several alkaloids besides nicotine, which is the main addiction factor. Just think of all the people who give up cigs for vapes. They manage on nicotine only. Some of the alkaloids in Nicotianas have significant MAOI effect.