In reply to Double Knee Bar:
If being alcohol-free makes you feel better and achieve more, did you ever ask why do you drink at all?
I used to drink (and smoke) a lot while I was younger teenager, but I haven't had any alcohol in my mouth (except Listerine!) for over year and half and haven't had a single cigarette for 3 years or so. And yes, I am just 20 now. I feel way much better, if you ask. I still consume lots of espresso every day, though.