Anecdotes are hardly useful in this one. Your reaction to Nicotine/Caffeine is probably unique. See: https://en.wikipedia.org/wiki/Substance_dependence#Psychol

Anecdotes are hardly useful in this one. Your reaction to Nicotine/Caffeine is probably unique. See: https://en.wikipedia.org/wiki/Substance_dependence#Psychological_dependence https://en.wikipedia.org/wiki/Substance_dependence#Psycholog... Dependence on substances is really complex. Environment, genetic and your current situation matters a lot (unless you are taking Heroin, I guess). Personally: I drink 4/6 coffees per day. Hardly any difference if I didn't drink. I usually drink coffee right before going to sleep too. For some people, it seems that coffee messes with their sleep cycle. For me, excess coffee gives me skin rashes.