My experience was that over time I coupled liking drink to wanting it. This "wanting" was different than just liking because it it was active rather than passive and drove me or motivated me to drink more of this substance that I liked and which gave me pleasure.
I at some point developed tolerance of course and although drinking still gave me pleasure it never reached matched earlier experiences. Throughout my later drinking days I kept going back to certain times, in particular a glass of red wine I had during an interlude at a concert talking with a woman I really liked - I think the pleasure was from the whole experience, the social aspect and drinking combined although drinking was certainly required to make the memory of this event so powerful in my mind. I think I was always trying to recreate feelings like this and this explains the "wanting" that my drinking had become. And, like you say zen, this took over and I didn't enjoy things I used to do such as socialising and sport as much. This has all come back to me since stopping though and I actually appreciate simple pleasures like these even more now.