[kakacik]

Dude, caffeine ain't no heroin. I drink 2-3 coffees a day and skipping this (ie traveling on vacation, easily for a week or two) does 0 to my body, mind or sleep. I just don't feel the effect at all, I drink it purely for the taste.

There is no human in this world who could say something similar about heroin.

[deepsun]

Sure, but your case is 1. There are many people addicted to caffeine, and it did affect their sleep and mind. (Writing this sipping my mandatory coffee :)