Last year when I quit I went cold turkey and basically obsessed over it for 2 weeks and was worthless to all around me.
This time seems scarily easy, tho maybe I haven't hit the wall yet.
Of course every time I start back up again, part of it is feeling like 'oh, quitting isn't THAT bad, I can do it again.' Part of it also is that the whole action of smoking is innately pleasurable, independent of satisfying the need to keep your serum nicotine level up. But for me the biggest part is that there's nothing really that replaces the license smoking gives you to periodically tell the world to fuck off and take 5 minutes where you're simply satisfying a sensual pleasure. The only thing close is going to the bathroom with a magazine for #2, but you can smoke way more often than you can shit.