I started at 16, switched to vaping about 23? quit at 27. I smoked about 1-2 packs a day, and when I switched to vaping did it constantly.
I don't think cravings this long are usual and suspect it's a result of how intense my addiction was/was the reason my addiction was so intense. There is limited medical literature on persistent cravings but it seems to happen to some people.
Deadset I found quitting morphine trivial compared to nicotine. Just fucking fuck idiot lonely teenaged me who found a way to make some friends. I don't blame that stupid goose barely hanging on but also fucking fuck them.