I have to put myself up in the 6 months or longer category...
My first attempts to quit smoking were back in the nineties. Yup, waaay back then. Never really had a problem actually as long as things went fine. Usually after a few weeks or months, I had a really bad and stressful day, lots of smokers around me and it was so damned easy to start again. The more I tried to quit, the harder it became. Patches, gums, whatever didn't do much for me. My addiction was less the nicotine and more that feeling of smoking, having something in my hands and the links to food, coffee, alcohol, ...
In 2011 I purchased my first e-cig... those ones that looked like cigarettes, remember? Not enough vapor production, not enough nicotine and felt more like a gadget than something worthy of a replacement.
In 2012 I tried it again, different brand... disgusting flavors that literally made me sick
2014 I got myself a bit of a larger vape pen from blue. It was OK but still not enough throat hit, nicotine etc to make me quit.
Then in 2016 I stopped buying stuff online and went into a vape shop the very first time. I tried a few devices and juices, just with the intention of dual use as I had given up on ever being able to quit. However, this Aspire MTL device has such great flavor, enough nicotine to give me a buzz so I had no more need for tobacco and before I knew it, I had actually quit smoking.
Quite a long way for me but it was mainly due to the availability and selection of devices and juices. Had I been given a proper ecig in the 90s, I would've quit right then. I don't miss smoking one bit... although I do miss having some herb every now and then lol
