Go with an open mind. I think people are a bit hesitant at first because they are comparing it to things they know like Six Flags or other regional amusement parks. It is nothing like anything you have ever experienced before. You will see grown men in Mickey ears and they will look normal, you will see little ones so excited seeing their favorite character that they can't speak. You will see strangers actually being nice to each other. It is a place that cannot be explained, only experienced. I was asked to explain Disney World to a father of 3 boys, ages 6, 8, and 13. They had never been and their mother booked the trip and told Dad to stay home if he didn't want to go, but they were. He went, grumbling. When I asked him to describe their trip, his first words were, "We are booked for the same time, same place next year!" Then, with tears in eyes, added, "I can never forgive myself for depriving them of something so wonderful for so many years."
Hope your trip is magical!