You're right, you don't understand it. At all. And how could you?
Alcohol affects different people differently. The way it triggers the pleasure centers in the brain of an alcoholic are far different than in that of a normal person.
Non-addicts will never truly understand where addicts are coming from. They can sympathize but not empathize. Only other addicts understand, that's why support groups like AA are so effective (relatively speaking).
Explaining addiction to my judgmental father or piers has been impossible. 10 years and no success.