What changed? Well - a lot of things, but the biggest thing I had to do was retrain my brain to be grossed out by booze and make the thoughts less sexy. This is easily accomplished by thinking about all of the gross effect alcohol (in excess) has on the body, such as:
Impotence (which is not sexy)
Pneumonia, Lung Collapse, and Pulmonary Infection (also, not sexy)
Balding (really not sexy)
Osteoporosis and arthritis (nobody wants the hunch back - not sexy)
You get the point, I'm sure.