If the rationale given by the other party is essentially, "Because I said so" (or the various ways people try to make their personal preference sound like something more than it is, such as by calling it "common sense"), then I typically remain unimpressed. However, if a reasonable, fact-filled counter is presented, I do change my mind. Up until April, I was an affirmed meat-eater. I even did the Atkins diet once. In April, a teen got up at church and outlined her reasons for being a vegetarian. I was convinced. I changed my mind and haven't had meat since. She didn't just say, "Don't eat meat because I don't want you to." She made a convincing argument about why eating meat was not necessary for most of us, and that meat came at the cost of the lives of other animals.