Caffeine is way more difficult to give up because you actually do get physically addicted to it. I'm a coffee fiend and drink about two pots of coffee a day. You'd think I'd be wired off all the caffeine but it no longer has any effect on me. It does fuck with my blood pressure though so the doc says I should quit but I can't. I'm not a weak minded person either. I smoked a pack of cigs a day for more than 15 years but managed to quit them 6 years ago. I also stopped smoking weed for about 5 years after many years of daily use. But the coffee, as much as I've tried I can't give it up.