I stopped at about 25 when I got my driving licence (a little later in life than most) and had to be 0.00 blood alcohol level for 3 years. I wasn't actually barred from drinking, but I'm spontaneous and I didn't want to be in a situation where I couldn't drive somewhere because I'd had a drink 8 hours earlier.
I think I've had a sum total of probably half a glass of spirits in the past few years...
