You've heard the old adage that "Opinions are like a_holes, everybody has one". But what about those opinions that we form before we have adequate information. I'm talking preconceptions here.
I've done it before--judged a book by its cover, formed an opinion before I knew the facts. And with alcoholism, I've had preconceived notions about what the alcoholic will do or what will happen in a particular situation. It's almost a Pavlovian response. If you experience enough chaos, disappointment, and let downs, then you come to believe that's all you'll ever get.
I suppose it's only natural to think that if 99% of the time you've had a bad experience around the alcoholic, then it's highly probable that bad experience will occur again. But sometimes you are pleasantly surprised.
For me, I've learned not to have high expectations of people in general. It's best if I just let myself be surprised when the 1% shows itself to be good. Fortunately, these days I find life with my alcoholic to be good most of the time. But I still have those preconceptions that nag at me. I have evidence that I could be let down at any time. So I keep my expectations low, mind my own business and generally follow my "gut" when it comes to feelings. If it walks like a duck and quacks like a duck, it might just be a duck.