"I've never smoked a cigarette but I have been addicted to caffeine multiple times in my life."

Woops, a little bit of liberty taken there. The caffeine-> nicotine comparison refers to the isolated stimulants, not the act of smoking. People don't seem to be primarily addicted to nicotine in the sense of a cigarette, but the combination of nic + everything else in there.

You don't have to smoke to get a nicotine fix. You don't even need tobacco products.