Well, I have been basically drinking to get hammered for about 6 years. I honestly don't think that I have done any serious brain damage but I can tell that my thinking has been alterd.
I have gone sober for 2 months. Did it earlier this year. Getting sober (for 2 months) wasn't hard. The hard part is changing everything about your life. I went back to my old friends and would go out drinking with them because I was so lonely and sick of sitting at my house on fri and sat nights watching TV. Im outgoing by nature and I needed to get out. Also, I would be very quick to anger when I was sober. I have never been a violent person but I think that was just part of the emotion of not drinking, trying to change life, and being lonely.
Also, when I would talk to people I would get nervous and I wasn't really able to think clearly. Especially if it was a girl I liked for example.