I've had some Glühwein over the weekend. It was pre-planned and all, an exception to my 'no-alcohol' rule. It was my first time drinking in four months, and I don't think I will repeat it soon (leaving room for an unhealthy, emotional Christmas or pre-Christmas meltdown here).
It was fun, for starters. I didn't drink much, so I didn't have to deal with a hangover or anything. I didn't embarrass myself, I didn't insult anyone. But! I was very cranky the next day. This may sound silly to you, but it's not. I lash out at the people around me (i.e. my girlfriend) and turn what could be a relaxing Sunday morning into a bickerfest. It took me until the late afternoon to get back to being normal. This is not good.
I have a baseline of anxiety running all the time, and alcohol only amplifies that. People tend to ascribe bad behaviour to alcohol (I was sooo drunk), but that's not correct. Alcohol isn't responsible for your actions, you are. Alcohol is a drug that helps you lose inhibitions and be more sociable, but it's still you underneath. I am anxious and irritable all the time. Drinking and then coming down from alcohol just puts a magnifying glass on that.