it's a surprisingly shitty drug. When recently I was in hospital, nil by mouth for ages and then they were late with the operation, I started getting this massive headache. I spoke to the anasthetic guy before surgery and told him about it and he tells me it's cos I hadn't had any caffeine for a long time. He was right, all I could think about was getting a coffee. Had to wait til I woke up again. Then I had three.
S'not even like I drink loads either, just two/three a day (that's not a lot is it?). I dunno, makes you think about giving it up....