> To the OP: curious to know, are you a user?
Yes. Reading the literature, I found no reason to not try out nicotine. I discuss my personal experiences in http://www.gwern.net/Nootropics#nicotine
> Have you been off nicotine longer than 2 months in the past year?
Why would I do that if I find it useful, as I do? But I have been keeping a log of nicotine use since June (to use it as a covariate in other self-experiments), which indicates I easily skip it for long periods: 03, 07 June 2013: 4mg gum; 22 June 2013: 2mg gum; 24 June 2013: 2mg gum; 1 July: 2mg gum; 9 July, 2mg gum; 20 July, 2mg gum; 20 August, 3mg gum; 5, 6 September, 1mg gum; 20 Sept, 1mg gum.
More generally, I received my current batch of nicotine gum (96x4mg) back on 28 December 2011, or 640 days ago; I still have 2 pieces left over, so that means I've been using the nicotine at an average rate of (94 * 4) / 640 = 0.6mg/day. (This includes the August-November 2012 period where I was taking gum every other day for a dual n-back experiment.)