I think it's the other junk in the analog. I craved for cigarettes for the first two weeks of vaping (no analogs during vaping). The "smoke" part was psychological, but the other chemical in the analog were very hard to kick.
After two weeks, my body has now only crave the nicotine, as that was the only thing that was constant between analog and vaping.
I finally caved in after two weeks of straight vaping (fruity flavored e-juices this whole time), and lit up an analog (I used to smoke about half a pack of reds a day), it was the grossest thing I've ever tasted (well, it took me back to the memory of my first puff with analog way back when). That analog helped me realize that I'm off of it for good. Could not stand the smell. After two puffs with that last analog, I was done.
I cleaned out my ashtray that I still had setup in my backyard, tossed the rest of the pack of analog in the trash, and the left over cartons of analogs are still just sitting there. I'm just too lazy to toss it out since I don't even notice them anymore.
I have lighters everywhere around my house, a reminder that when I smoked analogs, an available lighter everywhere around the house was a necessity. Nowadays, I may just replace those lighters with batteries and chargers...
Anyone that's still smoking analogs and vaping at the same time, just give vaping some time, pick some really good juices (Mt. Baker Vapor), and maybe visit a B&M once in a while to find your all day vape... There's a lot of juices that taste good, but not an all day vape...
Another thing you'll enjoy when you truly kick the analogs out of your life is your sense of smell and taste returns. I've gained quite a few pounds because candies and snacks tastes good! I used to never eat candies and snacks when I smoked analogs (probably because it gave everything an ashtray/burnt taste from the smoke)...