Never drank coffee while in the Army. I think I've said that before.
Here's one reason why: I was working for our S-2 who I thought was an old timer. He was a two-pack-a-day smoker and a multiple coffee thermos refiller.
One night, we were sitting around a fire/BBQ pit talking of retirement. The Major was complaining.
Me: What have you got to complain about, Sir? You could retire any time.
Major D.: Retire? @#$% you, LT! I'm thirty four years old!!!
To see what coffee does to an US Army Officer in Iraq, check out this MilBlog - Assumption of Command.