How long until nicotine is out of your system?

I quit smoking years ago by using nicotine chewing gum. Unfortunately, I got addicted to the gum instead. I chewed the gum for years. Three weeks ago, I went cold turkey and stopped using the gum. It wasn't as hard as I thought. After a couple of days, I was fine. Until yesterday.

Suddenly, I am having terrible nicotine fits, three weeks after having last ingested nicotine. Is it all psychological, or could the nicotine have lingered in my body this long?

Six years is a propaganda statement with no research to back it up. Before all the furor about smoking started in the last 10-15 years, the generaly accepted time from that the actual drug is in your system was 2 week to a month.

Now, with deeper research being completed, opinions vary, but the time frame is thought to be a little LESS overall.
According to York University, about a week.
According to life insurance companies, 72 hours.
And according to the previous answer to this question on Yahoo (sorry, didn't check the date), 48 hours.

I would say that your feelings are psychosomatic, which CAN last years, but usually subside to a bearable level in 4-6 weeks.

You need 6 years to get out of your system, but side effects can still be felt after that.