When I was in grad school, a business student friend of mine had to run a taste test between Classic Coke (which was just called "Coke" because New Coke had not yet been invented) and Pepsi. As a veteran coke drinker, I was sure I could tell the difference and promptly was proven wrong. (I still think that I can tell the difference and would like a rematch after 30+ years. This test occurred in a dorm room and ice was used. I think that it threw me off!)
Next, I hate diet, low-fat, non-fat, artificial sweetener, "light," "healthy," foods of all kinds. My girlfriend, an advocate of anything "healthy," bet me that I could not identify real eggnog from light eggnog. In a blind taste test, I lost--two Christmases in a row. (I am aiming for a rematch this December.)
Have you tried blind taste tests of your favorite brands? How were the taste tests set up? Were you able to tell the difference between your preferred brand and competitors?